The effectiveness of variable pitch cutter in suppressing chatter vibrations during milling has received extensive attention. An efficient precise integration-based full-discretization method is proposed for predicting stability of milling process with multiple delays that arise from variable pitch angle. The dynamic model of milling process considering helix angle is constructed and the state term and time delay term are approximated by linear interpolation method. Then

the stability lobe diagrams are obtained based on Floquet theory. In the process of stability prediction

the precise integration algorithm is used to avoid the inverse operation when solving the exponential matrix

which effectively improves the calculation efficiency. Finally

it shows that the proposed method is more efficient and accurate to predict the stability compared with the updated semi-discretization method.