Aiming at the problem that γ-TiAl-based alloy is difficult to process because of its brittleness at room temperature,a method to predict the cutting force in the milling machining of γ-TiAl-based intermetallic compound Ti-48Al-2Cr-2Nb by orthogonal oblique transformation was proposed.The basic cutting parameters such as shear stress,shear angle and friction angle were calculated by using the measurement results of chip thickness,cutting force and feed force in orthogonal turning test.The orthogonal oblique transformation technology was used to determine the milling coefficient,and the analytical model of cutting force for face milling was used to simulate the cutting force.In addition,the effects of coating on friction coefficient,shear stress,shear angle and cutting force were studied.Under different cutting conditions,the cutting force prediction results were verified by face milling and ball milling experiments.The results show that the predicted value of cutting force is in good agreement with the measured value,which verifies the validity of the mechanical model;for AlCrN and AlTiN coatings,the estimation error of cutting force in face milling is in the range of 20% and 13% respectively;for AlCrN coating,the estimation error of cutting force in ball milling is within the range of 15%.