Abstract: In order to realize the optimization of process parameters within a certain tolerance of drilling defects, the organization structure of the composites was tested to obtain the sectional morphologies and feature size of composite laminates by SEM. Then the orthogonal experiment was designed to test the thrust and torque, and the delamination, tearing and roundness error arising from drilling process were measured. The mechanism of defects was analyzed. The relevant variation was studied from the measured value by non-linear fitting. The relationships between the drilling defects and the thrust force, torque deviation were established to obtain the critical range respectively. At last, the spindle speed, feed rate and chisel edge eccentricity coefficient were selected as decision variables, and reaching the maximum material removal rate was chosen as the optimization goal, and the defects tolerance of drilling were selected as the constraint condition. And the parameter optimization model of drilling was established. The optimization of process parameters was realized with the MATLAB software to obtain the process parameters that ensure the maximum productivity and the suitable quality of composite drilling.