In this paper, firstly, the structural technology of plastic parts is analyzed, and the plastic materials are selected; Then the standard mold base, parting surface, exhaust mode and cavity distribution were determined; The gating system, the guiding and positioning mechanism, the demoulding mechanism, the side core pulling mechanism, the guide chute and the sliding block were designed, and the molding parts, cavity wall thickness, heating and cooling systems were calculated. Finally, the injection molding machine was checked.