The invention discloses a manufacturing method of a multilayer shell-core composite structural part, which comprises the following steps of: (1) respectively preparing feed for injection forming of a core layer, a
transition layer and a shell layer, wherein
powder in the feed of the core layer and the
powder in the feed of the shell layer are selected from one or a mixture of some of
metal powder,
ceramic powder, or toughened
ceramic powder and are different from each other, and the powder in the feed of the
transition layer is gradient composite powder; (2) respectively manufacturing blanks of the multilayer shell-core composite structural part layer by layer with a
powder injection forming method; (3)
degreasing the blanks; and (4)
sintering the blanks to obtain the multilayer shell-core composite structural part. The multilayer shell-core composite structural part is manufactured with the
powder injection forming method, and has the advantages of
high surface hardness, abrasion resistance, uniform thickness of the shell layer, stable and persistent performance,
strong binding force between the shell layer and the core layer due to the
transition layer, good integral bending strength and good
impact toughness and is difficult to crack.