Moldflow simulation analysis software was used to analyze the mold flow of the sensor back cover, studying the setting and optimization of process parameters such as filling time, clamp force, and injection pressure. Possible defects of the plastic part during the injection process were analyzed, such as: Air traps, weld lines, and warping deformation are timely proposed for modification measures, reducing the frequency of mold testing and repair, and improving the quality of plastic parts. Finally, the feasibility of model flow analysis was verified through experiments, and the produced sensor back cover met the requirements.