The traditional pneumatic brake system occupies large space for the compressor, brake reservoir and air pipe. Replacing the pneumatic brake system with electromechanical brate (EMB) system could reduce the space significantly. In addition, it could reduce the latency time and control the clamping force precisely. Taking electric urban bus as the research target, the scheme of EMB actuator was discussed. The locked torque and the noload speed were deduced according to the maximum clamping force of the traditional pneumatic disc brake. Based on this, a permanent magnet brushless direct current (BLDC) drive motor was designed, with the locked torque of 10 N·m and noload speed of 370 r/min. Then the finite element model of motor was established by using Maxwell 2D, and the braking performance during the phases of eliminating clearance and clamping force increasing was analyzed. The results showed that the braking performance of the designed drive motor could meet the requirements.