The invention provides a functional composite biological nutrient for the biochemical treatment of industrial wastewater. The functional composite biological nutrient is prepared by adopting the following steps: pulverizing a certain weight percentage of sodium phosphate, ferrous sulfate, magnesium sulfate, potassium chloride, zinc chloride, calcium carbonate, EDTA-2Na, starch, diammonium phosphate, ammonium molybdate, sodium silicate and copper sulfate into fine particles by a pulverizing machine, and agitating and mixing under the conditions of normal temperature and normal pressure after the fine particles are greatly larger than or equal to 20 mesh sieves. The invention has rich nutrition and high energy efficiency, is mainly used for the growth and the succession of microorganisms during the biochemical treatment process of the industrial wastewater and the quick and mass propagation of the microorganisms under the severe environment, promotes the formation of a zooglea with goodstructure, shields the toxicity of chemical leftovers to the microorganisms, accelerates the biochemical reaction, improves the treatment effect of a biochemical system, and particularly enables the biochemical treatment system to be quickly recovered as a buffer agent and a nutritive substance when the quality and the amount of the industrial wastewater are changed or sudden accidents occur.