diff --git a/api/core/app/apps/pipeline/pipeline_runner.py b/api/core/app/apps/pipeline/pipeline_runner.py
index 1249303285..78df0639bd 100644
--- a/api/core/app/apps/pipeline/pipeline_runner.py
+++ b/api/core/app/apps/pipeline/pipeline_runner.py
@@ -16,7 +16,6 @@ from core.repositories.factory import WorkflowExecutionRepository, WorkflowNodeE
 from core.workflow.node_factory import DifyNodeFactory, get_default_root_node_id
 from core.workflow.system_variables import build_bootstrap_variables, build_system_variables
 from core.workflow.variable_pool_initializer import add_node_inputs_to_pool, add_variables_to_pool
-from core.workflow.variable_prefixes import CHILD_SYNC_VARIABLE_NODE_IDS
 from core.workflow.workflow_entry import WorkflowEntry
 from dify_graph.entities.graph_init_params import GraphInitParams
 from dify_graph.enums import WorkflowType
@@ -275,7 +274,6 @@ class PipelineRunner(WorkflowBasedAppRunner):
                 invoke_from=invoke_from,
             ),
             call_depth=0,
-            child_sync_variable_node_ids=CHILD_SYNC_VARIABLE_NODE_IDS,
         )
 
         node_factory = DifyNodeFactory(
diff --git a/api/core/app/apps/workflow_app_runner.py b/api/core/app/apps/workflow_app_runner.py
index ded8fb0035..634f2e1e58 100644
--- a/api/core/app/apps/workflow_app_runner.py
+++ b/api/core/app/apps/workflow_app_runner.py
@@ -40,7 +40,6 @@ from core.workflow.system_variables import (
     inject_default_system_variable_mappings,
 )
 from core.workflow.variable_pool_initializer import add_variables_to_pool
-from core.workflow.variable_prefixes import CHILD_SYNC_VARIABLE_NODE_IDS
 from core.workflow.workflow_entry import WorkflowEntry
 from dify_graph.entities import GraphInitParams
 from dify_graph.entities.graph_config import NodeConfigDictAdapter
@@ -137,7 +136,6 @@ class WorkflowBasedAppRunner:
                 invoke_from=invoke_from,
             ),
             call_depth=0,
-            child_sync_variable_node_ids=CHILD_SYNC_VARIABLE_NODE_IDS,
         )
 
         # Use the provided graph_runtime_state for consistent state management
@@ -292,7 +290,6 @@ class WorkflowBasedAppRunner:
                 invoke_from=InvokeFrom.DEBUGGER,
             ),
             call_depth=0,
-            child_sync_variable_node_ids=CHILD_SYNC_VARIABLE_NODE_IDS,
         )
 
         node_factory = DifyNodeFactory(
diff --git a/api/core/workflow/variable_prefixes.py b/api/core/workflow/variable_prefixes.py
index 9574bc8a42..7664be0983 100644
--- a/api/core/workflow/variable_prefixes.py
+++ b/api/core/workflow/variable_prefixes.py
@@ -2,5 +2,3 @@ SYSTEM_VARIABLE_NODE_ID = "sys"
 ENVIRONMENT_VARIABLE_NODE_ID = "env"
 CONVERSATION_VARIABLE_NODE_ID = "conversation"
 RAG_PIPELINE_VARIABLE_NODE_ID = "rag"
-
-CHILD_SYNC_VARIABLE_NODE_IDS = frozenset((CONVERSATION_VARIABLE_NODE_ID,))
diff --git a/api/core/workflow/workflow_entry.py b/api/core/workflow/workflow_entry.py
index 22c855e7bf..c59fb3422b 100644
--- a/api/core/workflow/workflow_entry.py
+++ b/api/core/workflow/workflow_entry.py
@@ -15,7 +15,7 @@ from core.workflow.system_variables import (
     inject_default_system_variable_mappings,
 )
 from core.workflow.variable_pool_initializer import add_node_inputs_to_pool, add_variables_to_pool
-from core.workflow.variable_prefixes import CHILD_SYNC_VARIABLE_NODE_IDS, ENVIRONMENT_VARIABLE_NODE_ID
+from core.workflow.variable_prefixes import ENVIRONMENT_VARIABLE_NODE_ID
 from dify_graph.entities import GraphInitParams
 from dify_graph.entities.graph_config import NodeConfigDictAdapter
 from dify_graph.errors import WorkflowNodeRunFailedError
@@ -234,7 +234,6 @@ class WorkflowEntry:
                 invoke_from=InvokeFrom.DEBUGGER,
             ),
             call_depth=0,
-            child_sync_variable_node_ids=CHILD_SYNC_VARIABLE_NODE_IDS,
         )
         graph_runtime_state = GraphRuntimeState(
             variable_pool=variable_pool,
@@ -385,7 +384,6 @@ class WorkflowEntry:
                 invoke_from=InvokeFrom.DEBUGGER,
             ),
             call_depth=0,
-            child_sync_variable_node_ids=CHILD_SYNC_VARIABLE_NODE_IDS,
         )
         graph_runtime_state = GraphRuntimeState(
             variable_pool=variable_pool,
diff --git a/api/dify_graph/entities/graph_init_params.py b/api/dify_graph/entities/graph_init_params.py
index 66218517c0..f785d58a52 100644
--- a/api/dify_graph/entities/graph_init_params.py
+++ b/api/dify_graph/entities/graph_init_params.py
@@ -3,6 +3,8 @@ from typing import Any
 
 from pydantic import BaseModel, Field
 
+DIFY_RUN_CONTEXT_KEY = "_dify"
+
 
 class GraphInitParams(BaseModel):
     """GraphInitParams encapsulates the configurations and contextual information
@@ -20,7 +22,3 @@ class GraphInitParams(BaseModel):
     graph_config: Mapping[str, Any] = Field(..., description="graph config")
     run_context: Mapping[str, Any] = Field(..., description="runtime context")
     call_depth: int = Field(..., description="call depth")
-    child_sync_variable_node_ids: frozenset[str] = Field(
-        default_factory=frozenset,
-        description="Variable node IDs whose values must be synced back from child graph executions.",
-    )
diff --git a/api/dify_graph/graph_engine/event_management/event_handlers.py b/api/dify_graph/graph_engine/event_management/event_handlers.py
index f0c8eada17..e7a8291373 100644
--- a/api/dify_graph/graph_engine/event_management/event_handlers.py
+++ b/api/dify_graph/graph_engine/event_management/event_handlers.py
@@ -94,6 +94,10 @@ class EventHandler:
         Args:
             event: The event to handle
         """
+        if isinstance(event, NodeRunVariableUpdatedEvent):
+            self._dispatch(event)
+            return
+
         # Events in loops or iterations are always collected
         if event.in_loop_id or event.in_iteration_id:
             self._event_collector.collect(event)
diff --git a/api/dify_graph/nodes/iteration/iteration_node.py b/api/dify_graph/nodes/iteration/iteration_node.py
index c1c25aa0f9..e8c16ceb99 100644
--- a/api/dify_graph/nodes/iteration/iteration_node.py
+++ b/api/dify_graph/nodes/iteration/iteration_node.py
@@ -1,7 +1,7 @@
 import logging
 from collections.abc import Generator, Mapping, Sequence
 from concurrent.futures import Future, ThreadPoolExecutor, as_completed
-from contextlib import AbstractContextManager
+from contextlib import AbstractContextManager, nullcontext
 from datetime import UTC, datetime
 from typing import TYPE_CHECKING, Any, NewType, cast
 
@@ -36,7 +36,6 @@ from dify_graph.nodes.iteration.entities import ErrorHandleMode, IterationNodeDa
 from dify_graph.runtime import VariablePool
 from dify_graph.variables import IntegerVariable, NoneSegment
 from dify_graph.variables.segments import ArrayAnySegment, ArraySegment
-from dify_graph.variables.variables import Variable
 
 from .exc import (
     InvalidIteratorValueError,
@@ -203,11 +202,6 @@ class IterationNode(LLMUsageTrackingMixin, Node[IterationNodeData]):
                     graph_engine=graph_engine,
                 )
 
-                # Sync conversation variables after each iteration completes
-                self._sync_child_variable_snapshot(
-                    self._extract_child_variable_snapshot(variable_pool=graph_engine.graph_runtime_state.variable_pool)
-                )
-
                 # Accumulate usage from this iteration
                 usage_accumulator[0] = self._merge_usage(
                     usage_accumulator[0], graph_engine.graph_runtime_state.llm_usage
@@ -235,7 +229,6 @@ class IterationNode(LLMUsageTrackingMixin, Node[IterationNodeData]):
                         float,
                         list[GraphNodeEventBase],
                         object | None,
-                        dict[tuple[str, str], Variable],
                         LLMUsage,
                     ]
                 ],
@@ -260,7 +253,6 @@ class IterationNode(LLMUsageTrackingMixin, Node[IterationNodeData]):
                         iteration_duration,
                         events,
                         output_value,
-                        child_variable_snapshot,
                         iteration_usage,
                     ) = result
 
@@ -276,9 +268,6 @@ class IterationNode(LLMUsageTrackingMixin, Node[IterationNodeData]):
 
                     usage_accumulator[0] = self._merge_usage(usage_accumulator[0], iteration_usage)
 
-                    # Sync workflow-owned variable scopes after iteration completion
-                    self._sync_child_variable_snapshot(child_variable_snapshot)
-
                 except Exception as e:
                     # Handle errors based on error_handle_mode
                     match self.node_data.error_handle_mode:
@@ -302,7 +291,7 @@ class IterationNode(LLMUsageTrackingMixin, Node[IterationNodeData]):
         index: int,
         item: object,
         execution_context: AbstractContextManager[object],
-    ) -> tuple[float, list[GraphNodeEventBase], object | None, dict[tuple[str, str], Variable], LLMUsage]:
+    ) -> tuple[float, list[GraphNodeEventBase], object | None, LLMUsage]:
         """Execute a single iteration in parallel mode and return results."""
         with execution_context:
             iter_start_at = datetime.now(UTC).replace(tzinfo=None)
@@ -321,22 +310,21 @@ class IterationNode(LLMUsageTrackingMixin, Node[IterationNodeData]):
 
             # Get the output value from the temporary outputs list
             output_value = outputs_temp[0] if outputs_temp else None
-            child_variable_snapshot = self._extract_child_variable_snapshot(
-                variable_pool=graph_engine.graph_runtime_state.variable_pool
-            )
             iteration_duration = (datetime.now(UTC).replace(tzinfo=None) - iter_start_at).total_seconds()
 
             return (
                 iteration_duration,
                 events,
                 output_value,
-                child_variable_snapshot,
                 graph_engine.graph_runtime_state.llm_usage,
             )
 
     def _capture_execution_context(self) -> AbstractContextManager[object]:
         """Return the application-supplied execution context for parallel iterations."""
-        return self.graph_runtime_state.execution_context
+        execution_context = self.graph_runtime_state.execution_context
+        if execution_context is not None:
+            return execution_context
+        return nullcontext()
 
     def _handle_iteration_success(
         self,
@@ -510,26 +498,6 @@ class IterationNode(LLMUsageTrackingMixin, Node[IterationNodeData]):
 
         return variable_mapping
 
-    def _extract_child_variable_snapshot(self, *, variable_pool: VariablePool) -> dict[tuple[str, str], Variable]:
-        snapshot: dict[tuple[str, str], Variable] = {}
-        for node_id in self.graph_init_params.child_sync_variable_node_ids:
-            variables = variable_pool.variable_dictionary.get(node_id, {})
-            for name, variable in variables.items():
-                snapshot[(node_id, name)] = variable.model_copy(deep=True)
-        return snapshot
-
-    def _sync_child_variable_snapshot(self, snapshot: dict[tuple[str, str], Variable]) -> None:
-        parent_pool = self.graph_runtime_state.variable_pool
-        for node_id in self.graph_init_params.child_sync_variable_node_ids:
-            current_keys = set(parent_pool.variable_dictionary.get(node_id, {}))
-            snapshot_keys = {name for scope_node_id, name in snapshot if scope_node_id == node_id}
-
-            for removed_key in current_keys - snapshot_keys:
-                parent_pool.remove((node_id, removed_key))
-
-        for selector, variable in snapshot.items():
-            parent_pool.add(selector, variable)
-
     def _append_iteration_info_to_event(
         self,
         event: GraphNodeEventBase,
@@ -592,7 +560,6 @@ class IterationNode(LLMUsageTrackingMixin, Node[IterationNodeData]):
             graph_config=self.graph_config,
             run_context=self.run_context,
             call_depth=self.workflow_call_depth,
-            child_sync_variable_node_ids=self.graph_init_params.child_sync_variable_node_ids,
         )
         # Create a deep copy of the variable pool for each iteration
         variable_pool_copy = self.graph_runtime_state.variable_pool.model_copy(deep=True)
diff --git a/api/dify_graph/nodes/loop/loop_node.py b/api/dify_graph/nodes/loop/loop_node.py
index 34bfacec14..64a0535ef4 100644
--- a/api/dify_graph/nodes/loop/loop_node.py
+++ b/api/dify_graph/nodes/loop/loop_node.py
@@ -416,7 +416,6 @@ class LoopNode(LLMUsageTrackingMixin, Node[LoopNodeData]):
             graph_config=self.graph_config,
             run_context=self.run_context,
             call_depth=self.workflow_call_depth,
-            child_sync_variable_node_ids=self.graph_init_params.child_sync_variable_node_ids,
         )
 
         # Create a new GraphRuntimeState for this iteration
diff --git a/api/tests/unit_tests/core/workflow/graph_engine/test_table_runner.py b/api/tests/unit_tests/core/workflow/graph_engine/test_table_runner.py
index 2dec3580c0..aef32208d7 100644
--- a/api/tests/unit_tests/core/workflow/graph_engine/test_table_runner.py
+++ b/api/tests/unit_tests/core/workflow/graph_engine/test_table_runner.py
@@ -24,7 +24,6 @@ from core.tools.utils.yaml_utils import _load_yaml_file
 from core.workflow.node_factory import DifyNodeFactory, get_default_root_node_id
 from core.workflow.system_variables import build_bootstrap_variables, build_system_variables
 from core.workflow.variable_pool_initializer import add_node_inputs_to_pool, add_variables_to_pool
-from core.workflow.variable_prefixes import CHILD_SYNC_VARIABLE_NODE_IDS
 from dify_graph.entities.graph_init_params import GraphInitParams
 from dify_graph.graph import Graph
 from dify_graph.graph_engine import GraphEngine, GraphEngineConfig
@@ -206,7 +205,6 @@ class WorkflowRunner:
                 }
             },
             call_depth=0,
-            child_sync_variable_node_ids=CHILD_SYNC_VARIABLE_NODE_IDS,
         )
 
         system_variables = build_system_variables(
diff --git a/api/tests/unit_tests/core/workflow/test_workflow_entry_helpers.py b/api/tests/unit_tests/core/workflow/test_workflow_entry_helpers.py
index 5960230dd3..9945fb992f 100644
--- a/api/tests/unit_tests/core/workflow/test_workflow_entry_helpers.py
+++ b/api/tests/unit_tests/core/workflow/test_workflow_entry_helpers.py
@@ -7,7 +7,6 @@ import pytest
 from core.app.apps.exc import GenerateTaskStoppedError
 from core.app.entities.app_invoke_entities import InvokeFrom, UserFrom
 from core.workflow import workflow_entry
-from core.workflow.variable_prefixes import CHILD_SYNC_VARIABLE_NODE_IDS
 from dify_graph.entities.graph_config import NodeConfigDictAdapter
 from dify_graph.enums import NodeType
 from dify_graph.errors import WorkflowNodeRunFailedError
@@ -503,7 +502,6 @@ class TestWorkflowEntryHelpers:
             ),
             run_context={"_dify": "context"},
             call_depth=0,
-            child_sync_variable_node_ids=CHILD_SYNC_VARIABLE_NODE_IDS,
         )
         dify_node_factory_cls.assert_called_once_with(
             graph_init_params=sentinel.graph_init_params,
diff --git a/api/tests/workflow_test_utils.py b/api/tests/workflow_test_utils.py
index 60513d17fb..fad486f7e0 100644
--- a/api/tests/workflow_test_utils.py
+++ b/api/tests/workflow_test_utils.py
@@ -3,7 +3,6 @@ from typing import Any
 
 from core.app.entities.app_invoke_entities import InvokeFrom, UserFrom, build_dify_run_context
 from core.workflow.variable_pool_initializer import add_node_inputs_to_pool, add_variables_to_pool
-from core.workflow.variable_prefixes import CHILD_SYNC_VARIABLE_NODE_IDS
 from dify_graph.entities.graph_init_params import GraphInitParams
 from dify_graph.runtime import VariablePool
 from dify_graph.variables.variables import Variable
@@ -54,7 +53,6 @@ def build_test_graph_init_params(
             extra_context=extra_context,
         ),
         call_depth=call_depth,
-        child_sync_variable_node_ids=CHILD_SYNC_VARIABLE_NODE_IDS,
     )