diff --git a/api/dify_graph/nodes/loop/loop_node.py b/api/dify_graph/nodes/loop/loop_node.py
index a2d827f034..363f902f82 100644
--- a/api/dify_graph/nodes/loop/loop_node.py
+++ b/api/dify_graph/nodes/loop/loop_node.py
@@ -406,11 +406,12 @@ class LoopNode(LLMUsageTrackingMixin, Node[LoopNodeData]):
             SegmentType.ARRAY_OBJECT,
             SegmentType.ARRAY_STRING,
         ]:
-            if original_value and isinstance(original_value, str):
-                value = json.loads(original_value)
+            # New typed payloads may already provide native lists, while legacy
+            # configs still serialize array constants as JSON strings.
+            if isinstance(original_value, str):
+                value = json.loads(original_value) if original_value else []
             else:
-                logger.warning("unexpected value for LoopNode, value_type=%s, value=%s", original_value, var_type)
-                value = []
+                value = original_value
         else:
             raise AssertionError("this statement should be unreachable.")
         try:
diff --git a/api/tests/unit_tests/core/workflow/nodes/test_loop_node.py b/api/tests/unit_tests/core/workflow/nodes/test_loop_node.py
index 6372583839..b3904fe707 100644
--- a/api/tests/unit_tests/core/workflow/nodes/test_loop_node.py
+++ b/api/tests/unit_tests/core/workflow/nodes/test_loop_node.py
@@ -1,6 +1,9 @@
+import pytest
+
 from dify_graph.entities.graph_config import NodeConfigDictAdapter
-from dify_graph.nodes.loop.entities import LoopNodeData
+from dify_graph.nodes.loop.entities import LoopNodeData, LoopValue
 from dify_graph.nodes.loop.loop_node import LoopNode
+from dify_graph.variables.types import SegmentType
 
 
 def test_extract_variable_selector_to_variable_mapping_validates_child_node_configs(monkeypatch) -> None:
@@ -50,3 +53,21 @@ def test_extract_variable_selector_to_variable_mapping_validates_child_node_conf
     )
 
     assert seen_configs == [child_node_config]
+
+
+@pytest.mark.parametrize(
+    ("var_type", "original_value", "expected_value"),
+    [
+        (SegmentType.ARRAY_STRING, ["alpha", "beta"], ["alpha", "beta"]),
+        (SegmentType.ARRAY_NUMBER, [1, 2.5], [1, 2.5]),
+        (SegmentType.ARRAY_OBJECT, [{"name": "item"}], [{"name": "item"}]),
+        (SegmentType.ARRAY_STRING, '["legacy", "json"]', ["legacy", "json"]),
+    ],
+)
+def test_get_segment_for_constant_accepts_native_array_values(
+    var_type: SegmentType, original_value: LoopValue, expected_value: LoopValue
+) -> None:
+    segment = LoopNode._get_segment_for_constant(var_type, original_value)
+
+    assert segment.value_type == var_type
+    assert segment.value == expected_value