diff --git a/model/db.go b/model/db.go
index 068c4e7..4cb094f 100644
--- a/model/db.go
+++ b/model/db.go
@@ -42,21 +42,33 @@ func InitDB() error {
 func createRS485Table() error {
 	_, err := db.Exec(`
 		CREATE TABLE IF NOT EXISTS rs485_weather_data (
-			id SERIAL PRIMARY KEY,
+			id BIGSERIAL PRIMARY KEY,
 			station_id VARCHAR(50) NOT NULL,
-			timestamp TIMESTAMP NOT NULL,
-			temperature DECIMAL(5,2),    -- 温度（摄氏度）
-			humidity DECIMAL(5,2),       -- 湿度（%）
-			wind_speed DECIMAL(5,2),     -- 风速（m/s）
-			wind_direction DECIMAL(5,2),  -- 风向（度）
-			rainfall DECIMAL(5,2),       -- 降雨量（mm）
-			light DECIMAL(10,2),         -- 光照（lux）
-			uv DECIMAL(5,2),            -- 紫外线
-			pressure DECIMAL(7,2),       -- 气压（hPa）
-			raw_data TEXT,              -- 原始数据
-			FOREIGN KEY (station_id) REFERENCES stations(station_id)
+			timestamp TIMESTAMPTZ NOT NULL,
+			temperature DOUBLE PRECISION,
+			humidity DOUBLE PRECISION,
+			wind_speed DOUBLE PRECISION,
+			wind_direction DOUBLE PRECISION,
+			rainfall DOUBLE PRECISION,
+			light DOUBLE PRECISION,
+			uv DOUBLE PRECISION,
+			pressure DOUBLE PRECISION,
+			raw_data TEXT,
+			FOREIGN KEY (station_id) REFERENCES stations(station_id),
+			UNIQUE (station_id, timestamp)
 		)`)
-	return err
+	if err != nil {
+		return err
+	}
+
+	// 支持性索引（若已存在则不重复创建）
+	if _, err = db.Exec(`CREATE INDEX IF NOT EXISTS idx_rwd_time ON rs485_weather_data (timestamp)`); err != nil {
+		return err
+	}
+	if _, err = db.Exec(`CREATE INDEX IF NOT EXISTS idx_rwd_station_time ON rs485_weather_data (station_id, timestamp)`); err != nil {
+		return err
+	}
+	return nil
 }
 
 func CloseDB() {