Cutting force and cutting heat were both critical factors in machining of propellant grain.Two single-factor experiments were first designed to analyze the evolution of cutting force and cutting temperature during machining，followed by an orthogonal array cutting experiment to optimize the process parameters.The results show that increasing the feed rate causes the main cutting force，thrust force，and feed force to rise.Among the tools evaluated，polycrystalline diamond（PCD）tools yield the smallest main cutting and thrust forces.The feed rate has little influence on temperature，and PCD tools yield the lowest cutting temperature.After optimizing the process parameters of cutting，the overall minimum main cutting force and temperature are obtained at V_c=65 m/min，V_f=30mm/min，a_p=0.5 mm，γ₀=20°，α₀=15°.