Abstract: In order to study the influence of precision reducer and servo motor as core components on the performance of the industrial robot, an electromechanical coupling analysis, testing and evaluation method based on servo-precision transmission system is proposed. Taking the permanent magnet synchronous motor as the research object, the vector control mathematical model of the servo system and the double closed-loop motor vector control algorithm model are established. The operating quality model of the servo drive system is simulated, and the mapping relationship between the operating quality parameters and the key performance indicators of the whole machine is established. According to the static and dynamic characteristic parameters of the transmission system and core components, the performance degradation models of the reducer and the servo system were established respectively, and the parameter accuracy was evaluated through the accelerated life test. The results show that the influence on the performance of the whole machine is mainly reflected by 5 parameters such as the starting torque and torsional stiffness of the reducer, and 7 parameters such as the positioning error of the servo axis of the servo system and the following error.