Abstract: Based on the analyzing of the advantage of electromechanical actuator for tilting train, the situations of development and application of electromechanical actuator are introduced. The schemes of electromechanical actuator are given and analyzed, and the electromechanical actuator has been designed on the basis of comparing. The technical design of electromechanical actuator, such as the selection and force analysis of planetary roller screws, is introduced. The technical parameters and the stress calculation results of the main components are presented.