Abstract: This paper introduces the mathematical model of the permanent magnet synchronous motor (PWSM) and its corresponding control theory . Based on this, a model-reference adaptive control method is introduced into the AC servo system. This method can not only realize parameter self-correction, but also improve the robustness of the system. Simulation and experimental results show the effectiveness of this method. Keywords: PWSM, Adaptive Control, MRAS 1 Introduction Currently , AC motors are strongly coupled, multivariable, nonlinear, and time-varying systems, making their control much more complex. Many scholars have proposed different theories and control methods. The permanent magnet synchronous AC servo motor is a relatively complex controlled object. The actual controlled object model often has many uncertainties in controller design. Therefore, introducing adaptive control into a permanent magnet synchronous AC servo system can not only fully reflect its parameter self-correction characteristics but also greatly improve the system's robustness. This has profound significance both theoretically and academically. For details, please click to download: Application of Adaptive Control in Permanent Magnet Synchronous Motor Servo Systems