The invention provides a biodegradable multilayer co-extrusion material. The material is characterized by comprising two surface functional layers and a middle layer located between the two surface functional layers, components of the surface functional layers and the middle layer include biodegradable materials, and the biodegradable materials refer to one or more of polybutylene succinate, polylactic acid, polyhydroxyalkanoate and polybutylene adipate-polybutylene terephthalate. The invention further discloses a preparation method of the material. The biodegradablity of four selected master batches of the multilayer co-extrusion material is good, and adopted inorganic minerals are natural, so that the co-extrusion material has completely biodegradable properties and can be widely used in various types of food packages, medical products, environmental protection labels, advertisements and all kinds of environmental-protection products.