The traditional operating mechanism and the rotary motor operating mechanism take on complex structure, low reliability and large dispersion. The detent force of slot linear motor operating mechanism brings thrust pulsation, motor vibration and degradation of speed control. These factors lead to imprecise opening and closing of 12 kV Vacuum Circuit Breaker (VCB). In order to solve problems mentioned above, the Slotless Tubular Permanent Magnet Linear Synchronous Motor (STPMLSM) operation mechanism is proposed. According to the opening and closing characteristics, the structure and the parameters of STPMLSM are designed, with its mathematical model derived. The static and dynamic characteristics of the motor are simulated and analyzed by finite element method. The relationship between the motor electromagnetic force and time is obtained during the starting process, and the relationships among the movable contact travel, the speed and time are acquired. The results show that the motor structure parameters which are designed in this paper can meet the requirements of the circuit breaker switching characteristics, effectively suppress the thrust pulsation, and provide reliable foundations for the motor operating mechanism used in various voltage levels. This work is supported by National Natural Science Foundation of China (No. 51377106 and No. 51337001).