diff --git a/sanguo_portfolio/providers/local_unified_provider.py b/sanguo_portfolio/providers/local_unified_provider.py
index 7f31636..4dfd392 100644
--- a/sanguo_portfolio/providers/local_unified_provider.py
+++ b/sanguo_portfolio/providers/local_unified_provider.py
@@ -370,3 +370,120 @@ class LocalUnifiedProvider(DataProvider):  # type: ignore[misc]
         if bs_pcf is not None:
             row["pcf_ratio"] = float(bs_pcf)
         return row
+
+    # ==================== 辅助方法 ====================
+    def get_trade_days(
+        self,
+        start_date: Optional[Union[str, datetime]] = None,
+        end_date: Optional[Union[str, datetime]] = None,
+        count: Optional[int] = None,
+    ) -> List[datetime]:
+        """读 dbbardata 蓝筹 600519 distinct datetime 取交易日(全市场交易日一致)。"""
+        conn = self._connect()
+        rows = conn.execute(
+            "SELECT DISTINCT datetime FROM dbbardata WHERE symbol='600519' "
+            "AND exchange='SSE' AND interval='d' ORDER BY datetime"
+        ).fetchall()
+        days = [pd.Timestamp(r[0]).to_pydatetime() for r in rows if r[0]]
+        start_ts = pd.Timestamp(start_date) if start_date else None
+        end_ts = pd.Timestamp(end_date) if end_date else None
+        if start_ts:
+            days = [d for d in days if pd.Timestamp(d) >= start_ts]
+        if end_ts:
+            days = [d for d in days if pd.Timestamp(d) <= end_ts]
+        if count:
+            days = days[-count:]
+        return days
+
+    def get_security_info(self, security: str) -> Dict[str, Any]:
+        """读 dbbardata min/max datetime → start/end_date;display_name 从 constituent_unified。"""
+        sym, exc = jq_to_dbbardata(security)
+        conn = self._connect()
+        row = conn.execute(
+            "SELECT MIN(datetime), MAX(datetime) FROM dbbardata "
+            "WHERE symbol=? AND exchange=? AND interval='d'",
+            (sym, exc),
+        ).fetchone()
+        start_dt = row[0][:10] if row and row[0] else None
+        end_dt = row[1][:10] if row and row[1] else None
+        # display_name 查 constituent_unified
+        name = security
+        try:
+            nrow = conn.execute(
+                "SELECT code_name FROM constituent_unified WHERE code=? LIMIT 1",
+                (sym,),
+            ).fetchone()
+            if nrow and nrow[0]:
+                name = str(nrow[0])
+        except sqlite3.Error:
+            pass
+        return {
+            "code": security,
+            "display_name": name,
+            "name": name,
+            "start_date": start_dt,
+            "end_date": end_dt,
+            "type": "stock",
+        }
+
+    def get_current_tick(self, security: str) -> Optional[Dict[str, Any]]:
+        """dbbardata 最近 close + 高低涨停 ±10%(简化,ST/创业/科创精确规则 v2)。"""
+        sym, exc = jq_to_dbbardata(security)
+        conn = self._connect()
+        row = conn.execute(
+            "SELECT close_price FROM dbbardata WHERE symbol=? AND exchange=? "
+            "AND interval='d' ORDER BY datetime DESC LIMIT 1",
+            (sym, exc),
+        ).fetchone()
+        if not row or row[0] is None:
+            return None
+        close = float(row[0])
+        return {
+            "code": security,
+            "current_price": close,
+            "close": close,
+            "high_limit": round(close * 1.1, 2),
+            "low_limit": round(close * 0.9, 2),
+        }
+
+    def get_split_dividend(
+        self,
+        security: str,
+        start_date: Optional[Union[str, datetime]] = None,
+        end_date: Optional[Union[str, datetime]] = None,
+    ) -> List[Dict[str, Any]]:
+        """读 bs_adjust_factor → 除权事件列表。"""
+        bs_code = _jq_to_bs_code(security)
+        conn = self._connect()
+        start_str = self._to_date_str(start_date) or "1900-01-01"
+        end_str = self._to_date_str(end_date) or "2099-12-31"
+        try:
+            rows = conn.execute(
+                "SELECT dividOperateDate, foreAdjustFactor, backAdjustFactor, adjustFactor "
+                "FROM bs_adjust_factor WHERE code=? AND dividOperateDate>=? "
+                "AND dividOperateDate<=? ORDER BY dividOperateDate",
+                (bs_code, start_str, end_str),
+            ).fetchall()
+        except sqlite3.Error:
+            return []
+        return [
+            {
+                "code": security,
+                "date": r[0],
+                "foreAdjustFactor": float(r[1]) if r[1] is not None else None,
+                "backAdjustFactor": float(r[2]) if r[2] is not None else None,
+                "adjustFactor": float(r[3]) if r[3] is not None else None,
+            }
+            for r in rows
+        ]
+
+    def get_all_securities(
+        self, types: Optional[List[str]] = None,
+    ) -> pd.DataFrame:
+        """读 dbbardata distinct symbol → DataFrame[code, display_name]。"""
+        conn = self._connect()
+        rows = conn.execute(
+            "SELECT DISTINCT symbol, exchange FROM dbbardata WHERE interval='d'"
+        ).fetchall()
+        codes = [dbbardata_to_jq(sym, exc) for sym, exc in rows if sym and exc]
+        return pd.DataFrame({"code": codes, "display_name": codes})
diff --git a/tests/portfolio/test_local_unified_provider.py b/tests/portfolio/test_local_unified_provider.py
index 4db6f65..9132395 100644
--- a/tests/portfolio/test_local_unified_provider.py
+++ b/tests/portfolio/test_local_unified_provider.py
@@ -472,3 +472,61 @@ class TestGetFundamentals:
         p = LocalUnifiedProvider({"db_path": str(db), "data_dir": str(tmp_path)})
         df = p.get_fundamentals_df([], date="2024-09-30")
         assert df.empty
+
+
+# ======================== Task 4: 辅助方法 ========================
+class TestAuxMethods:
+    def test_get_trade_days_from_dbbardata(self, unified_provider):
+        # dbbardata 600519 三根日线 → 3 个交易日
+        days = unified_provider.get_trade_days(
+            start_date="2024-06-18", end_date="2024-06-20"
+        )
+        assert len(days) == 3
+        assert all(hasattr(d, "year") for d in days)
+
+    def test_get_trade_days_count(self, unified_provider):
+        days = unified_provider.get_trade_days(count=2)
+        assert len(days) == 2
+
+    def test_get_security_info(self, unified_provider):
+        info = unified_provider.get_security_info("600519.XSHG")
+        assert info["code"] == "600519.XSHG"
+        assert "start_date" in info
+        assert "end_date" in info
+
+    def test_get_current_tick_high_limit(self, unified_provider):
+        # dbbardata 最近 close=910 → high_limit=910*1.1=1001
+        tick = unified_provider.get_current_tick("600519.XSHG")
+        assert tick is not None
+        assert abs(tick["close"] - 910.0) < 1e-6
+        assert abs(tick["high_limit"] - 910.0 * 1.1) < 1e-2
+
+    def test_get_split_dividend_from_adjust_factor(self, unified_provider):
+        # bs_adjust_factor 有 1 个事件 → 1 条记录
+        events = unified_provider.get_split_dividend(
+            "600519.XSHG", start_date="2024-01-01", end_date="2024-12-31"
+        )
+        assert len(events) >= 1
+        assert "date" in events[0]
+
+    def test_get_all_securities_from_dbbardata(self, tmp_path):
+        # dbbardata distinct symbol → DataFrame
+        db = tmp_path / "t.db"
+        c = sqlite3.connect(str(db))
+        c.execute(
+            "CREATE TABLE dbbardata(symbol TEXT, exchange TEXT, datetime TEXT, interval TEXT)"
+        )
+        c.executemany(
+            "INSERT INTO dbbardata VALUES(?,?,?,?)",
+            [
+                ("600519", "SSE", "2024-06-19 00:00:00", "d"),
+                ("000001", "SZSE", "2024-06-19 00:00:00", "d"),
+            ],
+        )
+        c.commit()
+        c.close()
+        p = LocalUnifiedProvider({"db_path": str(db), "data_dir": str(tmp_path)})
+        df = p.get_all_securities()
+        assert len(df) == 2
+        assert "code" in df.columns
+        assert "600519.XSHG" in set(df["code"])