The design is based on control system of 51 series MCU intelligent soybean milk machine. The soybean milk machine can set the timing of making soybean milk and selectively make soybean milk with beans, coarse cereals, vegetables and fruits. The whole system has multiple functions such as detection of lack of water, automatic pulping, anti overflow detection, alarm and automatic heat preservation. The hardware circuit of the system includes ten parts, namely, MCU main control module, power module, water-level detection module, anti overflow detection module, temperature detection module, heating module, pulping module, alarm module, display module, and keyboard module. The system program is realized through assembly language to make the control system of the soybean milk machine have a relatively high intelligent level and a better application prospect and higher value in use on the basis of the effective combination of software and hardware.