The utility model provides a relief valve valve position state detection device. The utility model provides a relief valve valve position state detection device, include: relief valve, feedback pipeline, the control system who sets up the pressure measurement on the feedback pipeline and be connected with the pressure measurement electricity are provided with L shape through -hole on the flow tube piston of relief valve, be provided with first through -hole on the lateral wall of flow tube piston cylinder body, and the feedback pipeline is connected with first through -hole, when the valve clack was opened, L shape through -hole and first through -hole were just to the intercommunication, through the liquid inflow feedback pipeline of high -pressure system pilot line entering relief valve, pressure measurement for whether there is the liquid flow mistake on detecting the feedback pipeline, and has the liquid flow out -of -date on detecting the feedback pipeline, to control system output detection signal, control system for open the information according to the detected signal to the user output relief valve. The utility model provides a relief valve valve position state detection device can accurately acquire the off state that opens of relief valve.