The utility model relates to a spring safety valve set pressure debugs device, it includes pneumatic cylinder, piston, piston cover, O type circle, hydraulic pump, coupling nut. The device is placed between the last spring holder and spring shield of relief valve, through coupling nut with pneumatic cylinder and hydraulic pump connection, the during operation hydraulic pump injects the voltol oil into the piston below, the piston shifts up under the effect of hydraulic oil, piston up end roof pressure through effort compression safe valve spring, compresses the set pressure adjustable screw silk of screwing later on, fixed spring decrement when the relief valve on the spring shield. After the work, adjusting device is withdrawn from to the hydraulic pump pressure release. The utility model discloses a when the advantage was adjusted to the relief valve of high set pressure, major diameter spring, because manpower primary governor control adjustable screw silk is very difficult or even unable the regulation, the device had saved the manpower regulation, only needed among the accommodation process to revolve and twisted the adjustable screw silk, and is light, convenient, laborsaving.