The utility model discloses an electric power connector anti-high voltage backflow protection device comprising four electric power connection contacts, an insulation housing, an insulation sleeve cylinder, an insulation sheath pipe and a pressure spring; the rear end of the electric power connection contact penetrates an inner plate of the insulation housing and is fixed on the inner plate of the insulation housing through a fastening screw nut and a gasket; the insulation sleeve cylinder is sleeved outside the front end of the electric power connection contact, and the rear end of the insulation sleeve cylinder is fixed on the inner plate of the insulation housing; the insulation sheath pipe is embedded between the insulation sleeve cylinder and the electric power connection contacts, the pressure spring is sleeved on the electric power connection contact and positioned between the insulation sheath pipe and the inner plate of the insulation housing. The electric power connector anti-high voltage backflow protection device is simple in structure and convenient in usage, can effectively realize fast connection and separation between a lead cable and a power supply; the elastic telescopic insulation sheath pipe is sleeved outside the electric power connection contacts, so when the electric power connector is not connected, an outer end port of the insulation sheath pipe is higher than an outer end face of the electric power connection contact, thereby preventing human body from contacting with the electric power connection contacts, and preventing generation of electric shock accidents.