The identification of the dynamic coefficients is the key to realize accurate simulation of dynamic milling process. To enlarge the scope of dynamic simulation without ignoring edge force, an improved method is presented to calculate milling force coefficients. In this method, linear approximation of average milling force is integrated with multiple linear regressions by supposing that milling force coefficients are time invariant for small variation of feed rate. Therefore, both the shear coefficients and the edge coefficients can be calculated simultaneously. A comparison of simulated milling force with and without the edge force is illustrated and the result shows that the accuracy is higher if the edge force coefficients are considered. This method casts new light on fast and accurate simulation of the dynamic milling force in real industrial environment.