Abstract: Through analyzing the technological features of the up-cover and the mold flowing of the mouse shell, used UG to design a injection mold . Introduced in detail design process of design parting surface, cavity layout, gating system, temperature control system, core-pulling mechanism and exhaust system about injection mould of the up-cover and working process of the mold.At the same time,we analyze the mold filling、fill and pack and cool with MoldFlow Plastics Insight(MPI).