Belonging to the technical field of bioplastics, the invention relates to a microcapsule starch-based bioplastic and a preparation method. Technically, the invention aims to provide a microcapsule starch-based bioplastic and a preparation method. The method utilizes the characteristic that the capsule wall material and matrix resin have good compatibility, bonds polyvinyl alcohol and starch as thecore, employs polytetrafluoroethylene as the capsule wall material to coat starch so as to obtain microcapsules, and disperses the microcapsules in resin to obtain masterbatch, thus improving the compatibility of starch and resin, and enhancing the mechanical properties of the film. Also compared with the conventional modification treatment process of starch biomass materials, microencapsulationtreatment solves the problem of tedious steps and broadens the application fields.