The invention provides a method for improving the surface quality of an injection molding foaming formed plastic part. The method comprises the following steps that a, before injection molding starts,a die cavity is heated, and the interior of the cavity reaches a certain heating temperature; b, after the step a is conducted, the die cavity is closed, and foaming fusion plastic raw materials arerapidly injected into the die cavity; and c, after the step b is conducted, when the die cavity is about to be fully filled, a vacuum pumping mechanism arranged in a die is started, gas in the die isexhausted, the die cavity is filled with foaming fusion plastics, and after cooling and sizing, the plastic part is finally obtained. According to the method, the surface quality of the plastic part product can be obviously improved, and the plastic part product that the surface is high in gloss and free of flow marks and other defects, and inner air holes are evenly distributed can be obtained.