NOVELTY - Fermentation nutrient agent comprises packaged enzyme complex, composite bacteria, protein complex and molasses solution. The molasses solution is prepared by introducing 70-90% of liquid molasses, 5-15% of potassium humate, 1-3% of fulvic acid and 6-10% of trace elements into a liquid reactor and then mixing, stirring thoroughly, filling and packaging. The protein complex is prepared by mixing 40-60% of soybean meal, 20-40% of bone meal, 5-15% of fish meal and 5-15% of calcium lactate, carrying out aerobic fermentation using bacteria at 5-40 degrees C for 20-25 days.    USE - The fermentation nutrient agent is useful as a fertilizer for crops (claimed).    DETAILED DESCRIPTION - Fermentation nutrient agent comprises packaged enzyme complex, composite bacteria, protein complex and molasses solution. The enzyme-bacteria composite is prepared by selecting photosynthetic bacteria, lactic acid bacteria, yeasts and actinomycetes bacteria as leavening agent, adding the leavening agent, 70-90% of whey liquid, 5-15% of liquid milk, 6-10% of molasses solution and 1-3% of strain liquid into a closed reactor liquid mixing system and then stirring, carrying out microbial strains immune activation, rejuvenation and propagation, standing for 15-20 days until the biological activity of bacteria reaches greater than or equal to 200 million/g and then filling and packaging. The molasses solution is prepared by introducing 70-90% of liquid molasses, 5-15% of potassium humate, 1-3% of fulvic acid and 6-10% of trace elements into a liquid reactor and then mixing, stirring thoroughly, filling and packaging. The protein complex is prepared by mixing 40-60% of soybean meal, 20-40% of bone meal, 5-15% of fish meal and 5-15% of calcium lactate, carrying out aerobic fermentation using bacteria at 5-40 degrees C for 20-25 days. An INDEPENDENT CLAIM is included for use of nutrient agent as fertilizer, where the application method comprises collecting fresh wild green weeds and then trimming and introducing into a container, adding nutrient agent and water into the container and carrying out sealed anaerobic fermentation for 7-10 days.