Abstract: In order to realize the milling force prediction of multi-axis milling， a new method based on the instantaneous milling force values was presented to obtain the specific milling force coefficients of ball-end milling. The instantaneous coordinate system of cutter was set up to precisely describe the position and posture of cutter during the process of milling. And on this basis the universal prediction model of milling， which includes the models of the edge length， the chip width in each cutting edge discrete element and the unreformed chip thickness， was established. Then according to the universal prediction model， the identification model of milling force coefficients based on the instantaneous milling force values was derived. The presented method was validated by experiments of milling force coefficients identification and the simulations of milling force.

Key words: multi-axis milling, milling force, coefficients of milling force, coefficients identification, modelling, simulation