The kinematic parameters of CNC machine tool multi-axis linkage milling process change greatly,leading to the increase of machining path tracking error and time.A new CNC machine tool multi-axis linkage milling process path fast tracking method was proposed.The instantaneous coordinate system for the multi-axis simultaneous milling tool and workpiece of CNC machine tool was constructed to realize the transformation between them.According to the transformation results of coordinate system,the kinematics model of multi-axis simultaneous milling of CNC machine tool was established.The fast tracking of motion trajectory in the process of milling was realized by combining the kinematics model and strong tracking Kalman filter trajectory tracking method.The experimental results show that this method can realize the trajectory tracking of any target point on the milling blade,the trajectory tracking error is less than 0.1 μm,and the average tracking time is less than 1.2 ms.It can quickly achieve high-precision milling trajectory tracking,and provides guarantee for improving the milling quality.