Abstract: The lightweight and integrated design of nodular cast iron engine body is the main direction of the engine body design and production. The engine body is also one of the castings that is more difficult to cast, and its casting process methods are also constantly explored and updated. This paper mainly explores and optimizes the V-type engine body process through 3D printing casting technology, using the whole core to maximize the reduction of the number of sand cores, solve complex structural design, improve production efficiency, improve the dimensional consistency of the body castings, and reduce appearance and internal defects. The production results show that the casting process solution designed by the research and development can solve the complex structure forming and casting production process more simple and efficient, the product dimensional accuracy is higher, and the appearance and internal quality are greatly improved.