A method for optimizing layout design of cooling water jacket channel of a CNC machine tool spindle is provided. The method comprises the following steps: the equivalent model is constructed first, and then the finite element model of the base structure is initialized, and the flexible growth unit is constructed, the finite element analysis is carried out, the adaptive growth is carried out, growth competition and configuration reconstruction are iterated under the updating of an MMA algorithm until the material consumption reaches the maximum value beta0 set when initialization. The inventioncan obtain the performance parameters of the water jacket through the finite element method in the design stage, improves the reliability of the design, has higher design efficiency compared with thetraditional design, can obtain better design results, and simultaneously reduces the design cost.