Finite element analysis was made on the modified power head bracket of GDZ-300L drill with ANSYS Workbench to demonstrate the safety and reliability of the structure; the power head bracket design was optimized by using software of Design-Xplorer VT multi-objective optimization model, the influence of each panel thickness to the bracket in equivalent stress and mass are analyzed. On the premise of ensuring the structure strength, a set of optimal solutions are obtained to save structure material and reduce manufacturing cost.