A novel permanent magnet motor actuator on high voltage circuit breaker is proposed. Based on the characteristics requirement of the circuit breaker, a limited angle permanent magnet brushless DC servo motor actuator is designed. By using the finite element method, the basic characteristics and dynamic simulation of starting are carried out, which the simulation results of the motor (such as electromagnetic torque, current, speed and location parameters) have been analyzed. The analysis is indicated that the rotary motor actuator can provide the mechanism characteristics and so it can supply a basis for vacuum circuit breaker using the rotary motor actuator.