NOVELTY - Method for preparing microbial fertilizer, involves mixing 18-26 pts. wt. Aspergillus niger (CGMCC 7927) culture, 3-5 pts. wt. Bacillus megaterium agent, 10-20 pts. wt. Lactobacillus plantarum (CGMCC 7928) agent and 25-36 pts. wt. B.subtilis (CGMCC 7926) agent. The B.subtilis agent is prepared by culturing B.subtilis strain in inclined plane to obtain B.subtilis fermentation liquid, and drying the fermentation liquid.    USE - The method is useful for preparing microbial fertilizer (claimed).    ADVANTAGE - The method improves microecological environment of soil, and growth of crops, decomposes soil organic matter e.g. humus, and organic phosphorus in soil and hence enables utilization of available phosphorus by plant, and enables less dosage, where the amount of fertilizer applied to land is 50-100 g/mu.    DETAILED DESCRIPTION - Method for preparing microbial fertilizer, involves mixing 18-26 pts. wt. Aspergillus niger (CGMCC 7927) culture, 3-5 pts. wt. Bacillus megaterium agent, 10-20 pts. wt. Lactobacillus plantarum (CGMCC 7928) agent and 25-36 pts. wt. B.subtilis (CGMCC 7926) agent. The B.subtilis agent is prepared by culturing B.subtilis strain in inclined plane to obtain B.subtilis fermentation liquid, and drying the fermentation liquid. The L.plantarum agent prepared by culturing L.plantarum in inclined plane, expanding the L.plantarum seed culture, transferring the expanded seed culture of L.plantarum to fermentation tank, performing fermentation at low temperature and under vacuum, concentrating the fermented product to original volume of 45% to obtain bacterial concentrated liquid, adding carrier to the concentrated liquid, uniformly mixing the concentrated liquid with carrier in a weight ratio of 0.5-0.7:1, and drying the mixture in fluidized bed at 50 degrees C. The carrier comprises 20-40 pts. wt. calcium carbonate and 10-20 pts. wt. dextrin. The A.niger culture is prepared by performing solid fermentation of the A.niger culture, drying the culture at 60 degrees C in fluidized bed or using other drying device till the water content of the culture is less than 10%, and pulverizing the dried solid culture to obtain product of 60 meshes. An INDEPENDENT CLAIM is included for method for preparing microbial fertilizer, which involves (A) culturing the B.subtilis, (B) preparing L.plantarum agent, and (C) preparing A.niger culture.