AC permanent magnet synchronous motor servo control system is a complex nonlinear, strong coupling and time-varying system. It has strong uncertainty and nonlinearity, and when the system is running, it also will be disturbed to varying degrees, so the conventional control strategy is difficult to meet the control requirements of high accuracy, high speed and high-performance servo system. This paper adopts a direct feedback linearisation control strategy based on sensor technology and uses, as the output of the system to realise the decoupling of the system. In addition, the grey prediction is added to overcome the shortcomings of direct feedback linearisation that is sensitive to parameters. Adjusting the uncertain factors block by grey prediction to adapt to the direct feedback linearisation rule and achieve the desired effect. MATLAB/Simulink is used to complete the simulation of servo control algorithm. The simulation results show that the direct feedback linearisation control is better than the conventional PID control, and the direct feedback linearisation control algorithm with grey prediction can improve the performance of the permanent magnet synchronous motor servo control system and can meet the basic requirements of the high-performance servo control system.