In the fields of modern industrial automation，robotics，high-precision computer numerical control machine tools， and aerospace and other cutting-edge equipment manufacturing，servo control systems serve as the key link for achieving precise motion execution， with their performance directly determining the response speed， positioning accuracy， and operational stability of the entire system. As the core feedback unit of the servo system，the rotating system servo position encoder undertakes the critical task of acquiring the real-time position，speed，and motion direction of the motor rotor，and its performance fundamentally restricts the control quality of the servo loop. Firstly，this paper analyzes the technical principles of four types of rotating system servo position encoders，namely photoelectric，resolver，magnetoelectric，and inductive encoders. Then，this paper elaborates on the core signal processing algorithms，accuracy levels，as well as their advantages and disadvantages in engineering applications，aiming to provide a certain theoretical supports and practical references for relevant researchers.