The utility model discloses a high-pressure safety detecting device for an electric car. An insulating detecting circuit is connected with an input end of a fault diagnosis unit through a voltage conditioning circuit; a temperature sensor is connected with the input end of the fault diagnosis unit through a temperature conditioning circuit; a current sensor is connected with the input end of the fault diagnosis unit through a current signal conditioning circuit; an output end of the fault diagnosis unit is connected with the input end of a vehicle-mounted whole-vehicle controller through a vehicle-mounted communication module; the output end of the vehicle-mounted whole-vehicle controller is connected with a control end of a vehicle-mounted high-pressure electric device; a parameter display alarm module is connected with the fault diagnosis unit; an electrifying fault detecting circuit is mounted between a vehicle-mounted storage battery and the vehicle-mounted high-pressure electric device. The high-pressure safety detecting device has the characteristics of high reliability, high detecting precision and complete detecting fault information.