Taking the automobile left and right support brackets as examples,by analyzing its shape structure characteristics,the Moldflow software was used to analyze the mold flow of 1 mould with 2 cavities(for left and right brackets).The whole wall thickness,filling time during in-jection,weld mark,warping deformation,shrinkage deformation,temperature at the front of flow and pressure at the end of filling were analyzed.According to the analysis results,the parting sur-face,core,cavity plate,and pushing mechanism of the mould were designed.The actual produc-tion verified that the mould structure was reasonable,and ran smoothly,and the accuracy and pass rate of the plastic parts met the customer's requirements.