Disclosed is a soybean milk preparation method of soybean milk preparation equipment. The soybean milk preparation equipment comprises a machine base (11), a holding device (13) for carrying a material packet (12), a liquid supply mechanism (14) and an injection head (15), wherein the holding device, the liquid supply mechanism and the injection head are arranged on the machine base, and one end of the injection head is in communication with the liquid supply mechanism and the other end thereof is aligned with the material packet. The material packet comprises a container (122) and a diaphragm (121) for sealing the container, the container comprising a bottom wall (1221) and a side wall (1222) extending upwards from the bottom wall, and the diaphragm covering an opening of the container. The soybean milk preparation method comprises the following steps: (a) the injection head passes through the diaphragm to inject a liquid into the material packet, and the liquid penetrates a soybean powder layer to reach a planar, concave or convex splashing part at the bottom of the material packet to form a fluid flow channel and (b) the injection head continues to inject the liquid into the material packet, the liquid is splashed by the splashing part to gradually dissolve the soybean powder upwards from the bottom of the material packet until the soybean powder is completely dissolved. A discharge hole is provided, and soybean milk in the material packet is pressurized and discharged via the discharge hole.Linvention concerne un procédé de préparation de lait de soja pour un équipement de préparation de lait de soja. Léquipement de préparation de lait de soja comprend un socle de machine (11), un dispositif de support (13) servant au support dun paquet de matière (12), un mécanisme dapport de liquide (14) et une tête dinjection (15). Le dispositif de support, le mécanisme dapport de liquide et la tête dinjection sont disposés sur le socle de machine. Une extrémité de la tête di
