diff --git a/casbin_async_sqlalchemy_adapter/adapter.py b/casbin_async_sqlalchemy_adapter/adapter.py
index e16d365..3a02c94 100644
--- a/casbin_async_sqlalchemy_adapter/adapter.py
+++ b/casbin_async_sqlalchemy_adapter/adapter.py
@@ -17,7 +17,7 @@
 
 from casbin import persist
 from casbin.persist.adapters.asyncio import AsyncAdapter
-from sqlalchemy import Column, Integer, String, delete
+from sqlalchemy import Column, Integer, String, delete, insert
 from sqlalchemy import or_
 from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
 from sqlalchemy.future import select
@@ -190,14 +190,20 @@ async def add_policy(self, sec, ptype, rule):
 
     async def add_policies(self, sec, ptype, rules):
         """adds a policy rules to the storage."""
-        if self._external_session is not None:
-            # Use external session to add all rules in the same transaction
-            for rule in rules:
-                await self._save_policy_line(ptype, rule, self._external_session)
-        else:
-            # Use individual sessions for each rule (original behavior)
-            for rule in rules:
-                await self._save_policy_line(ptype, rule)
+        if not rules:
+            return
+
+        # Build rows for executemany bulk insert
+        rows = []
+        for rule in rules:
+            row = {"ptype": ptype}
+            for i, v in enumerate(rule):
+                row[f"v{i}"] = v
+            rows.append(row)
+
+        async with self._session_scope() as session:
+            stmt = insert(self._db_class)
+            await session.execute(stmt, rows)
 
     async def remove_policy(self, sec, ptype, rule):
         """removes a policy rule from the storage."""
diff --git a/tests/test_adapter.py b/tests/test_adapter.py
index 960f632..26ace47 100644
--- a/tests/test_adapter.py
+++ b/tests/test_adapter.py
@@ -399,5 +399,42 @@ async def test_update_filtered_policies(self):
         self.assertTrue(e.enforce("bob", "data2", "read"))
 
 
+class TestBulkInsert(IsolatedAsyncioTestCase):
+    async def test_add_policies_bulk_internal_session(self):
+        engine = create_async_engine("sqlite+aiosqlite://", future=True)
+        adapter = Adapter(engine)
+        await adapter.create_table()
+
+        rules = [
+            ("u1", "obj1", "read"),
+            ("u2", "obj2", "write"),
+            ("u3", "obj3", "read"),
+        ]
+        await adapter.add_policies("p", "p", rules)
+
+        async_session = async_sessionmaker(
+            engine, expire_on_commit=False, class_=AsyncSession
+        )
+        async with async_session() as s:
+            # count inserted rows
+            from sqlalchemy import select, func
+
+            cnt = await s.execute(
+                select(func.count())
+                .select_from(CasbinRule)
+                .where(CasbinRule.ptype == "p")
+            )
+            assert cnt.scalar_one() == len(rules)
+
+            rows = (
+                (await s.execute(select(CasbinRule).order_by(CasbinRule.id)))
+                .scalars()
+                .all()
+            )
+            tuples = [(r.v0, r.v1, r.v2) for r in rows]
+            for r in rules:
+                assert r in tuples
+
+
 if __name__ == "__main__":
     unittest.main()