Abstract: Based on the analysis of the interior decoration model of column A, the gate was determined as a latent side gate, four points of feeding was selected, and the mold was designed a structure with “one mold and two cavities”. According to the analysis of injection molding process the melt temperature was determined as 232 ℃, the holding pressure was set to 105 MPa, the holding time was set as 7 s, and the cooling time was set as 29 s. The plastic volume shrinkage rate in average was 3.42 % for the injection-molded part under this condition. After verifying this group of technical parameters in injection molding, the acoustic port characteristics of the interior trim of column A are formed perfectly, and there is no defect caused by the slender internal flow passage. The clearance between the overall contour and fixture was within the allowable range.