The invention relates to a method for producing water-soluble fertilizers, in particular to a method for producing the water-soluble fertilizers with biochemical humic acid. The method is characterized by including matrix fermentation, concentrated liquor preparation and finished product preparation: firstly, weighing prepared concentrated liquor; secondly, adding modifiers, heating and stirring the liquor in the whole process, controlling the temperature to range from 40 DEG C to 60 DEG C, and cooling the liquor to be below 30 DEG C after reaction to obtain the fertilizers; and thirdly, packaging the fertilizers. The mass ratio of the concentrated liquor, the modifiers and inorganic auxiliary materials is (55-80): (0.1-2): (20-45). The method is simple in manufacture, easy in operation and high in actionability, solves the problem of water solubility of organic fertilizers, provides nutrition, improves soil, prevents diseases and insect pests, and integrates the effects of fertilizer supplementation, bacterium resistance and disease resistance. The fertilizers have balanced nutrition, stable state and persistent fertilizer effects, crop yield can be remarkably improved, the quality of agricultural products is improved, and soil fertility is enhanced.