The utility model provides an oil reservoir protective valve, is including the male joint still and time male joint is connected with urceolus both ends respectively, the urceolus in be located the male joint and be equipped with down a hydraulic control butterfly valve between the male joint, hydraulic control butterfly valve be close to down male joint one end and be connected with a single current valve body, this hydraulic control butterfly valve one side still is equipped with a balanced screw, should a balanced screw cavity formation balancing hole, be equipped with a spring rails between balance screw and the hydraulic control butterfly valve valve body, the tip that hydraulic control butterfly valve is close to last male joint is the infundibulate spigot surface, is equipped with a valve block in the middle of the spigot surface, the single current valve body is equipped with one -way valve ball, this check valve is inside have the passageway and with the balancing hole intercommunication, hydraulic control butterfly valve leads to for one side internally piloting formation passageway fuel feeding liquid stream at balanced screw place.