diff --git a/backend/init_db.py b/backend/init_db.py
new file mode 100644
index 0000000..8d807ab
--- /dev/null
+++ b/backend/init_db.py
@@ -0,0 +1,44 @@
+"""Quick DB init script - creates tables and seeds admin user."""
+import sys
+sys.path.insert(0, ".")
+
+from app.database import init_db, SessionLocal
+from app.models.tenant import Tenant
+from app.models.user import User
+from app.core.security import hash_password
+
+print("Initializing database...")
+init_db()
+print("Tables created.")
+
+db = SessionLocal()
+
+# Default tenant
+t = db.query(Tenant).filter(Tenant.slug == "default").first()
+if not t:
+    t = Tenant(name="默认租户", slug="default")
+    db.add(t)
+    db.flush()
+    print(f"Created tenant: {t.name} (id={t.id})")
+else:
+    print(f"Tenant exists: {t.name} (id={t.id})")
+
+# Admin user
+u = db.query(User).filter(User.email == "admin@test.com").first()
+if not u:
+    u = User(
+        email="admin@test.com",
+        username="admin",
+        hashed_password=hash_password("admin123"),
+        role="tenant_admin",
+        user_type="human",
+        tenant_id=t.id,
+    )
+    db.add(u)
+    db.commit()
+    print(f"Created admin user: {u.email} (id={u.id}, tenant_id={u.tenant_id})")
+else:
+    print(f"Admin user exists: {u.email}")
+
+db.close()
+print("Done!")