A manufacturing method of a multilayer shell-core composite structural component comprises the following procedures: (1) respectively preparing feeding material for injection forming of a core layer, a buffer layer and a shell layer, wherein the powders of feeding material of the core layer and the shell layer are selected from one or more of metallic powder, ceramic powder or toughened ceramic powder, and are different from each other, and the powder of feeding material of the buffer layer is gradient composite material powder; (2) layer by layer producing the blank of multilayer shell-core composite structural component by powder injection molding; (3) degreasing the blank; and (4) sintering the blank to obtain the multilayer shell-core composite structural component. The multilayer shell-core composite structural component has the advantages of high surface hardness, abrasion resistance, uniform thickness of the shell layer, stable and persistent performance.