Accurate prediction of milling force of five axis CNC machine tool is helpful to improve the machining quality of workpiece.Therefore,a dynamic compensation method was proposed to predict the milling force of five axis machine tools.The structure of five axis CNC machining center was analyzed,the feed transmission dynamics of the five axis CNC milling center was studied;by measuring the cutting torque,the total torque transmitted by the motor was calculated,and the transfer function between it and the frequency response of the measurement disturbance was calculated under the action of the impact force.The actual cutting torque was decomposed into DC (static) component and AC (harmonic) component,on this basis,the interference Kalman filter was used to attenuate the noise and the influence of structural dynamic mode on the cutting torque of interval sampling was compensated,so the measurement distortion caused by structural dynamic mode was reduced.The Denavit-Hartenberg method was introduced to calculate the conversion relationship between the cutting force and torque on the tool in the workpiece frame and the driving force and torque in the driving frame through Jacobian matrix,and then the tool tip force was mapped to the driving torque to realize the prediction of milling force.The results show that the force signal predicted by using this method is almost consistent with the measured force signal,indicating that the method can be used to accurately predict the milling force of five axis machine tool.