The most widely used manufacturing process for the production of plastic parts is injection molding. The produced parts, particularly the thin-walled ones, typically have a tendency to be distorted, which is very easily to be tended. How to reduce the warpage of the thin-walled product become a major problem to plastic manufacturer to control the quality of the molded part produced. An optimization of injection molding process parameters of the thin shell part using Differential Evolution (DE) method is suggested in this paper. A three-pin terminal cover of an electric kettle was used in this research as thin shell plastic part. The simulation software which is Autodesk Moldflow Insight 2012 (AMI) used in this research to identify the recommended process parameter settings which will be used into Response Surface Methodology (RSM) to gain the mathematical model and able to optimize process parameter setting using Differential Evolution (DE) method. The DE optimization method has been reduced the warpage on the molded part by 33.36% for y-axis direction and 11.64% for z-axis direction. So that, this study helps to produce quality injection molding parts with less time consuming and the production run with high accuracy process parameter setting.