The invention relates to the technical field of brakes, in particular to an electronic mechanical braking device with a self-reinforcement structure. Comprising a shell, the shell is detachably installed on a
brake caliper body and detachably connected with a cover body, a motor is installed in the shell, an output shaft of the motor is fixedly connected with a transmission shaft, the cover body is rotationally connected with a
butt joint shaft, a composite transmission mechanism is arranged between the transmission shaft and the
butt joint shaft, and the composite transmission mechanism is used for transmitting the transmission shaft and the
butt joint shaft. The position, away from the cover body, of the butt joint shaft is fixedly connected with a sleeving shaft
barrel, and the sleeving shaft
barrel is in spline connection with a transmission piece. The transmission mode between the transmission shaft and the butt joint shaft is changed, the
brake pad and the
brake disc are rapidly attached through the
low transmission ratio, then the rotating speed is reduced through the
high transmission ratio, the torque is increased, the
friction force between the
brake pad and the brake disc is increased, and therefore in the braking process, the
moving speed of the
brake pad is increased, and the braking response speed is increased.