A compound expanded plastic tray comprises a surface layer and a core layer, and the surface layer wraps the exterior of the core layer, wherein the surface layer is prepared from high density polyethylene, alkali-free glass fiber, a coupling reagent, talcum powder, a lubricant and an antioxidant; the core layer is prepared from high density polyethylene, a foaming agent, EVA, a blowing promoter, talcum powder, a coupling reagent, a lubricant and an antioxidant. The tray surface is relatively high in intensity, smooth and wear-resistant, and the core layer is relatively light in weight, so that an effect of weight losing is achieved. According to a preparation method of the compound expanded plastic tray, injection molding is carried out by a double-component injection molding machine, the hollow tray surface is formed by the surface layer materials, and then the core layer materials are injected into a space in the tray surface from the same sprue. The preparation process of the compound expanded plastic tray is simple and convenient in operation, and a product can be recycled.