The invention discloses a manufacturing method of a casting mold for a steel casting molding process. By applying SolidWorks three-dimensional modeling software and UG (Unigraphics NX) digital modeling software and employing the processing technology of a digital pattern-less casting precision molding machine, corresponding positions of process elements: a gating and riser system, a chilling block, a core iron and a deformability material and the like, included in the steel casting molding process are processed and reserved; then, a steel brick tube, a thermal insulation bush required by a riser, the chilling block, the corn iron and the deformability material are put into a processed sand mold, and are assembled and fixed, and casting is performed to obtain a product. Compared with a traditional production mode of manufacturing a pattern according to a traditional casting molding process and manufacturing the sand mold by utilizing the pattern to form the casting mold, the productionmode of the manufacturing method disclosed by the invention does not need to manufacture a solid pattern and does not need to consider the factors: the drafting angle and the like, so that the dimensional precision of the casting is increased; the billet weight of the casting can be reduced by 3 % to 5 %; and meanwhile, the problem that a traditional pattern for new product development and new process verification is long in manufacturing period and high in cost is solved.