This study focuses on the application of different injection molding processes to analyze the shear stress caused by uneven distribution by the influence of warpage. We explore the results from various sets of control parameters for injection, the auto locks using CAE simulation performance analysis and optimization of process parameters combination of warpage. In the research, we look for each single objective optimization process combined with Taguchi Robust Design process with L 18 (2 1 ×3 7 ) orthogonal. The control factors are injection time, the material temperature, mold temperature, injection pressure, packing pressure, packing time, cooling liquid and cooling tube flow rate. From the results of warpage and shear stress as a performance index, we calculate the performance index of the signal to noise ratio (SNR). Using the optimal process parameters, the optimal warpages of 1.294mm, 0.163mm are obtained, which are lower than total warpage values of the original process parameters. The total values of warpage is improved by 11.2%.