Abstract: In this paper, the molding technology of face recognizing machine cover was analyzed and the design of a hot runner injection mold for this part was introduced. At first, Moldflow software was employed to analyze the flow in the mold, the optimal gate locations and number were determined. Subsequently the structure and size of the hot runner were designed through comparing with cold runner system. Besides, based on Moldflow analysis, an inverse-moving mold structure and a distance parting mechanism were designed to meet the requirements of molding precision, with the antidirection pushing-out realized. At last, the total mold assembling drawing was finished.