The invention discloses an improved washing machine cover plate injection molding process including an injection molding system and an injection molding mold which are adopted to carry out the process. The process comprises the following steps of raw material mixing, stirring, raw material pretreatment, device pretreatment, raw material plastifying, mold closing, raw material injection, pressure keeping, cooling for molding, mold opening, molded housing taking, mold cleaning, inspection, finished product warehousing, crushing and screening. The cooling time is short and uniform, the process implementing steps are simple, an injection molding period of the product is effectively shortened, the production cost of the product is effectively reduced, meanwhile the quality of the finished product is effectively improved under the corresponding process conditions, and environmental protection is facilitated.