In order to improve the machined surface quality of CFRP parts and the tool life,the tool structure was optimized.The orthogonal experiment between the tool structure parameters and the machined surface roughness of CFRP parts and the wear of the tool flank were designed.The influence of the tool structure parameters on the surface roughness of CFRP and the tool flank wear were analyzed by the extreme difference analysis.The mathematical models between the tool structure parameters and the surface roughness of CFRP and the tool flank wear were established by the multiple linear regression method.Based on this model,the tool structure parameters were optimized by using firefly algorithm and the verification experiment was carried out.The results show that the influence sequence of the tool structure parameters on the surface roughness of the CFRP workpiece is as follow:the rear angle,the helix angle,the front angle.Within the range of the test parameters,when the rear angle,the helix angle and the front angle increase,the surface roughness decrease,but the degree of reduction are different.The influence sequence of the tool structure parameters on the tool flank wear is in turn:the rear angle,the helix angle,the front angle.When the rear angle of the tool increases,the tool flank wear increases rapidly,and when the helix angle increases,the tool flank wear decreases.When the front angle of the tool increases,the tool flank wear decreases firstly and then increases.The tool structure optimized by firefly algorithm is used to milling the CFRP.The error value between the experiment and the prediction is small.The error value of the surface roughness is only 3%,and the error value of tool flank wear is 7.6%.