Abstract: Aimed at the difficulty in the formation of plastic parts with a large wall thickness, shrinkage and deformation, a gas?assisted injection molding process was determined by CAE analysis. After the optimization for this injection mold, a single?point side?gate was adopted for gating, and a two?point gas port was applied for gas?assisted forming. With the optimized injection parameters, the shrinkage deformation of plastic parts could be controlled within 0.3 %~0.42 %. Based on the analysis of CAE, a gas?assisted two?plate injection mold with two cavities and two opening was designed. A compound twice?core?pulling half slider mechanism and a universal angle pin half slider mechanism were set up to carry out side core pulling and demolding. In these compound mechanisms, the first opening between the moving plate and moving?base plate on the moving mold side was adopted to realize the core pulling of the inclined core, and then the second opening between the fixed plate of fixed mold and the moving plate of moving mold was applied to drive the two half?sliders to carry out the side?core?pulling. The CAE optimization analysis played a very important role in the structural design of gas?assisted injection mold and it was advantageous to the improvement of overall design efficiency.