Based on the Multibody System Theory and homogeneous coordinate transformation，the relative motion and kinematic error between different parts were characterized, then the kinematic accuracy model of machine tool under movement was established,the dynamic sensitivity was analyzed and some key steps were given. The results show that direction and value constant or change according to different scenarios. Based on dynamic sensitivity analysis, the prediction model of dynamic error for machine tool was established, by input of some terms of simulated error, the tool path was obtained.