On the basis of reviewing the essential characteristics of microcellular plastics,the mechanism,technical characteristics and primary influencing factors of injection molding of microcellular plastics are emphatically discussed.And,the up-to-date technical trends of processing technics and the major working principle used for microcellular plastics by injection molding at home and abroad are introduced.In the end,a few representative application examples are given in accordance with the processing trait and advantages of the microcellular plastics.