Abstract: In the machining of a stainless steel thin-walled sleeve parts due to excessive cutting force caused by the machining accuracy of the parts difficult to guarantee the problem, where the geometric parameters of the tool is an important reason affecting the size of the cutting force. A method of optimizing the front angle, back angle and main deflection angle of the tool to reduce the cutting force is studied, a cutting simulation model is established, the maximum cutting force is calculated, the geometric parameters of the tool are established as a function of the cutting force, and the geometric parameters of the tool are optimized by the whale algorithm. The results show that the established function is more accurate and the cutting force is reduced by 16.99% after the optimization of tool parameters by the whale algorithm, which has a significant effect on improving the machining quality of the part.