By using the single factor test method,the high-speed milling test of titanium alloy was carried out with the insert carbide milling coated shoulder milling cutter to study the influence of feed per tooth,milling width,milling depth and milling speed on the milling force.By analyzing the milling force,the milling force model of high-speed milling of square shoulder milling cutter was established.The minimum milling force was used in the feed direction by MATLAB genetic algorithm.The milling parameters were optimized and the optimal solution set was given.The experimental results show that the use of optimized parameters for processing thin-walled parts can effectively reduce the cutting force.