A design method and process for automatic mechanical transmission(AMT) shift actuation are presented. Based on the requirement of the shifting force and the national standard 28 working conditions, the synchronous process and affecting factors to synchronous force of gear-shifting are analyzed for drawing up the dynamic and economic shift law followed the prototype vehicle performance parameters. The electromechanical shift actuators of the kinematics and dynamics are studied, then the maximum synchronous force is calculated. Finally, the parameters of the electromechanical shift actuator are determined. It is a foundation for electromechanical shift actuators design of automatic transmission and AMT control algorithm formulating.