The invention discloses a nano-zinc oxide reinforced starch/PBAT degradable material and a preparation method thereof. A packing film is prepared from the following raw materials in parts by weight: 10-30 parts of starch, 70-90 parts of PBAT, 3-12 parts of glycerin, 0.3-1.2 parts of a release agent, 0-2 parts of nano-zinc oxide, 0.2-1.5 parts of lauric acid and 0.1-0.9 part of a compatilizer, wherein the using amount of dichloromethane is that the mass ratio of the volume of the dichloromethane to the PBAT is (4 to 8) mL:1 g. The glycerin, the lauric acid and the compatilizer are added in thestarch gelatinization process to modify the starch, thus the plastified modified starch is prepared, then the starch and the PBAT serve as film forming base materials, the PBAT is completely dissolvedwith the help of a dichloromethane solvent, the starch and the nano-zinc oxide are evenly dispersed in the solvent, the release agent is added, and finally, the nano-zinc oxide reinforced cassava starch/PBAT thin film is prepared. The film preparation process is simple and easy to implement, the prepared thin film has good mechanical properties and water resistance, low light transmittance and water absorption rate, and high contact angle, can be completely biodegraded, has certain practical value, and can be used for the fields such as garbage bags, packaging bags having no requirement for sanitation, agricultural land films and industrial films.