针对光学系统中对非球面元件的精度要求，设计了直线光栅式的抛光轨迹，并用磁性复合流体以这一抛光轨迹抛光非球面。根据抛光轨迹和非球面方程计算出每个抛光点的坐标；根据抛光点坐标和抛光头的抛光姿态计算出对应的抛光头中心点的坐标；建立相邻两抛光点的弓高误差模型，仿真出弓高误差模型并分析弓高误差的变化规律；根据弓高误差变化规律，用等弓高误差变步长控制算法实现弓高误差的一致性，提高加工质量。

According to the accuracy requirements of aspheric components in the optical systems, the linear grating polishing trajectory of magnetic compound fluid polishing is designed to polish aspheric compoents. Based on the polishing trajectory and the aspheric equation, the coordinates of each polishing processing point are calculated. The coordinates of the center point of the polishing head are calculated according to each polishing point and the polishing head which is relative to the geometry of the workpiece. The model of high-height error between each polishing point is established, and the variation rule of the surface arch error of workpiece is simulated by the model. According to the variation rule of the surface arch error, the equal arch error control algorithm is used to achieve arch error consistency and improve processing quality.