Abstract: A car-used electric fuel pump including a hollow housing enclosing a fuel inlet member, a fuel outlet board, a DC motor and a fuel outlet member, wherein the fuel outlet board is formed with an eccentric groove for receiving an outer and an inner rotors which are engaged with each other. By means of the rotation of the outer and inner rotors, a fuel-sucking and discharging effect is created. The DC motor is connected with the inner rotor by a connecting member for driving the inner rotor. The connecting member permits the motor to be assembled with the inner rotor without high accuracy so that the assembling procedure is facilitated. A gas-escaping valve is disposed on the fuel outlet member, whereby hot air or steam in the pump is able to escape therefrom to carry away heat and lower the temperature of the pump for avoiding danger.