The invention relates to a method for preparing a black bean and corn nutrient solution. The black bean and corn nutrient solution is characterized by taking the following grains and vegetables as raw materials in parts by weight: 50-70 parts of black beans, 30-50 parts of corns, 20-40 parts of carrots, 10-20 parts of wheat, 20-40 parts of polished round-grained rice, 10-20 parts of sticky rice, 10-20 parts of green beans, 10-20 parts of cowpeas, 5-10 parts of black sesame and a proper amount of monosodium glutamate. The method specifically comprises the following steps of: cleaning the selected black beans, corns, wheat, polished round-grained rice, sticky rice, green beans and cowpeas; weighing the cleaned black beans, corns, wheat, polished round-grained rice, sticky rice, green beans and cowpeas according to the corresponding weight ratio and soaking the weighed black beans, corns, wheat, polished round-grained rice, sticky rice, green beans and cowpeas for 4-6 hours; putting the soaked black beans, corns, wheat, polished round-grained rice, sticky rice, green beans and cowpeas, the cleaned carrots and the proper amount of monosodium glutamate into a grinding machine, adding water according to a ratio of 1 to (5-15), grinding and filtering out a nutrient solution; adding the weighed black sesame into the filtered nutrient solution, heating to 100 DEG C, cooling, packaging, casually inspecting and selling. The black bean and corn nutrient solution has the effects of promoting skin metabolism, improving skin, nourishing and growing black hairs, tonifying spleen and kidney, and building a body, and is pure natural healthy food which is simple to produce and low in cost.