diff --git a/InsightEngine/agent.py b/InsightEngine/agent.py
index e58fa57c0..3670dba5c 100644
--- a/InsightEngine/agent.py
+++ b/InsightEngine/agent.py
@@ -32,6 +32,7 @@
 )
 from .utils import format_search_results_for_prompt
 from .utils.config import Settings, settings
+from .utils.deduplication import build_result_dedup_key
 
 ENABLE_CLUSTERING: bool = True  # 是否启用聚类采样
 MAX_CLUSTERED_RESULTS: int = 50  # 聚类后最大返回结果数
@@ -378,8 +379,8 @@ def _deduplicate_results(self, results: List) -> List:
         unique_results = []
 
         for result in results:
-            # 使用URL或内容作为去重标识
-            identifier = result.url if result.url else result.title_or_content[:100]
+            # Use full content and source metadata for URL-less results.
+            identifier = build_result_dedup_key(result)
             if identifier not in seen:
                 seen.add(identifier)
                 unique_results.append(result)
diff --git a/InsightEngine/utils/deduplication.py b/InsightEngine/utils/deduplication.py
new file mode 100644
index 000000000..5a65c1e1d
--- /dev/null
+++ b/InsightEngine/utils/deduplication.py
@@ -0,0 +1,32 @@
+"""
+Search-result deduplication helpers.
+"""
+
+from typing import Any, Tuple
+
+
+def build_result_dedup_key(result: Any) -> Tuple[Any, ...]:
+    """
+    Build a stable deduplication key for a search result.
+
+    URL-backed results keep the historical URL-only behavior. Results without a
+    URL need the full content and source metadata so distinct comments or posts
+    are not collapsed just because they share a long prefix.
+    """
+    url = getattr(result, "url", None)
+    if url:
+        return ("url", url)
+
+    publish_time = getattr(result, "publish_time", None)
+    if publish_time is not None and hasattr(publish_time, "isoformat"):
+        publish_time = publish_time.isoformat()
+
+    return (
+        "content",
+        getattr(result, "platform", None),
+        getattr(result, "content_type", None),
+        getattr(result, "source_table", None),
+        getattr(result, "author_nickname", None),
+        publish_time,
+        getattr(result, "title_or_content", "") or "",
+    )
diff --git a/tests/test_insight_deduplication.py b/tests/test_insight_deduplication.py
new file mode 100644
index 000000000..6c0643f9a
--- /dev/null
+++ b/tests/test_insight_deduplication.py
@@ -0,0 +1,61 @@
+import importlib.util
+from pathlib import Path
+from types import SimpleNamespace
+
+
+def load_deduplication_module():
+    module_path = (
+        Path(__file__).resolve().parents[1]
+        / "InsightEngine"
+        / "utils"
+        / "deduplication.py"
+    )
+    spec = importlib.util.spec_from_file_location("insight_deduplication", module_path)
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module
+
+
+deduplication = load_deduplication_module()
+
+
+def test_url_less_results_do_not_dedupe_by_truncated_prefix():
+    prefix = (
+        "Breaking: Major vulnerability found in popular framework "
+        "CVE-2026-1234 with remote code execution impact affecting millions "
+        "of users worldwide. "
+    )
+    first = SimpleNamespace(
+        url=None,
+        platform="weibo",
+        content_type="comment",
+        source_table="weibo_note_comment",
+        author_nickname="alice",
+        publish_time=None,
+        title_or_content=prefix + "No patch is needed.",
+    )
+    second = SimpleNamespace(
+        url=None,
+        platform="weibo",
+        content_type="comment",
+        source_table="weibo_note_comment",
+        author_nickname="alice",
+        publish_time=None,
+        title_or_content=prefix + "Patch immediately.",
+    )
+
+    assert first.title_or_content[:100] == second.title_or_content[:100]
+    assert deduplication.build_result_dedup_key(first) != deduplication.build_result_dedup_key(second)
+
+
+def test_url_results_keep_url_based_deduplication():
+    first = SimpleNamespace(
+        url="https://example.com/post/1",
+        title_or_content="Original content",
+    )
+    second = SimpleNamespace(
+        url="https://example.com/post/1",
+        title_or_content="Updated content",
+    )
+
+    assert deduplication.build_result_dedup_key(first) == deduplication.build_result_dedup_key(second)