In order to solve the disadvantages of long start-up time and demagnetization of the traditional permanent magnetic actuators, this paper presents a high reliability and controllable motor actuator without permanent magnet, which including driving motor and its control circuit. The proposed driving motor is similar to the switched reluctance motor which has the advantages of small rotational inertia and fast start-up. The difference is that there is an auxiliary coil which is placed between the two-stator sets and can be energized by controllable DC current to adjust the air-gap flux density that the output torque and the velocity of movable contact is easier to control. Furthermore, a prototype of the novel motor actuator has been developed according to the analysis and calculation results of dynamic characteristics of 40.5-kV Vacuum Circuit Breaker (VCB), which is tested on the platform in conjunction with a 40.5-kV VCB prototype to showcase the success of the proposed motor actuator and its control method.