For NC machine with permanent magnet linear synchronous motor (PMLSM),in the high speed and high precision machining,uncertain factors seriously affect the control performance of the servo system,such as the system decay,the external dis-turbances,parameter variations and so on. The predictive robust control system was proposed based on combining the model predictive controller (MPC)with disturbance observer (DOB). The MPC was used as the feedforward controller,through model prediction, rolling optimization and feedback correction to improve the tracking performance of the system;DOB was used to observe and suppress external load uncertainty disturbance. So the robustness of the system is improved,to achieve the objective of improving system tracking performance and robustness. Simulation results show that the proposed method is feasible and effective,can obviously improve the con-trol precision of the system.