The embodiment of the invention discloses a torque control method and device of an electronic power-assisted braking system. The system involves an electric control unit, a motor, a brake demand inputunit and a brake force generation unit, wherein the electric control unit is connected with the motor, the brake demand input unit comprises a brake pedal and a pedal travel sensor connected with theelectric control unit, the brake force generation unit comprises a rack, a piston and a brake fluid, and the rack is connected with the motor and the piston. The method comprises the steps that pedalopening information is received, and basic target torque of the motor is calculated according to pedal opening degree information; the actual environment temperature is obtained, and the compensationtarget torque of the motor is determined according to the actual environment temperature; the final target torque of the motor is calculated according to the basic target torque and the compensationtarget torque; and a torque control signal is sent to the motor according to the final target torque, and the motor is controlled to drive the rack to push the piston to move according to the torque control signal. According to the scheme, the actual brake deceleration and the braking deceleration requirement of the vehicle at different temperatures are consistent.