Main combustion cast pipe complex cavity casting mold/core forming method

The invention provides a main combustion cast pipe complex cavity casting mold/core forming method, which belongs to the technical field of sand mold casting, and comprises the following steps: designing a parting surface at the center of a bent pipe according to the outline of a main combustion cast pipe, and enabling the parting surface to be parallel to the plane of a thick and large flange; according to the shape and size of the complex cavity of the main combustion cast pipe, three-dimensional modeling is conducted on the mold core through three-dimensional cartographic software, an obtained three-dimensional model is divided into blocks, all the blocks are manufactured through the three-dimensional printing technology and assembled, and the mold core is obtained; a main combustion cast pipe pouring system adopts a horizontal pouring and vertical pouring process, and a bottom pouring type pouring system is adopted, so that stable mold filling is realized; feeding the main combustion cast pipe by adopting