The invention provides a soybean milk making method of a soybean milk machine so as to solve the problems existing in the making process of an existing soybean milk machine, particularly, the problems that noise is too large and the making cycle is too long. A smashing cover is arranged on a machine head of the soybean milk machine. The soybean milk making method is characterized by comprising the steps that firstly, a mixture of materials and water is heated to boil, the materials are softened and float to the liquid surface, and part of the materials are blocked and limited in the smashing cover; then, the boiling state is kept for a preset time, the materials are smashed with a smashing cutter in the kept boiling state, and at the moment, the materials are gradually taken into the smashing cover to be smashed under flowing of slurry; then, the materials are continuously smashed with the smashing cutter; finally, the mixture of the materials and the water continues to be heated so that the materials can be thoroughly cooked. According to the method, the slurry is heated to boil firstly, the boiling state is kept for a certain time, and the materials are smashed in the state, so that soybean milk making noise is greatly reduced, the soybean milk making cycle is shortened, and energy is saved.