Using corn starch as matrix and bamboo powder as reinforcing body, glycerol/phthalates (DOP) mixed as plasticizer, Azo dimethylamine/zinc oxide (AC/ZnO) as foaming agent, polyvinyl alcohol (PVA) as compatibility agent, natural fiber reinforced starch composite (NFSC) was prepared by injection molding foaming method. By studying the effects of the ratio and addition of different auxiliaries on the compatibility, mechanical properties, plasticizing effect and foaming effect of NFSC, the formulation design was optimized to improve the properties of the materials in order to obtain high quality-lightweight starch based thermoplastic foaming materials. The results showed that the quality ratio of glycerin/DOP being 6:1, and when the quality fraction was added to 30%, the plasticizing effect of NFSC was good. The quality ratio of AC/ZnO being 2:1, and when the quality fraction was added to 3%, the foaming effect of NFSC was good, and when the quality fraction of PVA was about 11%, the interface compatibility between bamboo powder and starch matrix was better.