NOVELTY - Compound microbial fertilizer preparation involves selecting active humic acid. 20-50% selected humic acid, 0-20% organic material, 30-60% inorganic nitrogen phosphorus potassium fertilizer and 2-3% trace element are added in a stir groove. Water is added to the obtained material, and then mixed to obtain slurry. The obtained slurry is granulated, and then dried in a dryer at 100-300 degrees C to obtain humic acid composite microorganism fertilizer master batch. Culture medium is prepared by mixing sodium chloride, beef extract and peptone in the ratio of 1-3:1-2:2-4.    USE - Method for preparing compound microbial fertilizer (claimed).    ADVANTAGE - The method enables to prepare compound microbial fertilizer that improves soil fertility and soil granule structure, activates plant rhizosphere, reduces fertilizer dosage and soil-borne disease, and enhances disease resistance and stress resistance property.    DETAILED DESCRIPTION - Compound microbial fertilizer preparation involves selecting active humic acid. 20-50% selected humic acid, 0-20% organic material, 30-60% inorganic nitrogen phosphorus potassium fertilizer and 2-3% trace element are added in a stir groove. Water is added to the obtained material, and then mixed to obtain slurry. The obtained slurry is granulated, and then dried in a dryer at 100-300 degrees C to obtain humic acid composite microorganism fertilizer master batch. Culture medium is prepared by mixing sodium chloride, beef extract and peptone in the ratio of 1-3:1-2:2-4. Distilled water or tap water is added to the mixed material, and then pH is adjusted to 7.2-8 to using dilute solution of sodium hydroxide or hydrochloric acid. Agar (1-3 times) is added, and then heated at 115-125 degrees C for 25-35 minutes. The obtained material is cooled to obtain solid culture medium. The strain is cultured in solid culture medium at 25-35 degrees C for 22-26 hours, and then stored in a refrigerator at 3-5 degrees C to obtain liquid strain. The obtained liquid strain is cultured in culture medium at 25-35 degrees C for 8-12 hours, which comprises 0.3-0.8 wt.% corn powder, 0.3-0.8 wt.% soybean powder, 0.2-0.5 wt.% dextrose or glucose, 0.2-0.5 wt.% bone meal and 0.1-0.4% peanut oil, where the pH of culture medium solution is adjusted to 7 using diluted solution of sodium hydroxide or hydrochloric acid. The culture medium is heated at 115-125 degrees C for 25-35 minutes, and then cooled. The obtained liquid strain is cultured in fermentation culture medium, which comprises 1.5-2.5% soybean powder, 1.8-3% corn rice floor, 0.3-0.8% bone meal, 0.1-0.4% peanut oil, 0.3-0.8% sweetening agent, 0.3-0.8% calcium chloride, 0.01-0.08% monopotassium phosphate and 0.01-0.16% dipotassium hydrogen phosphate, where the pH of culture medium solution is adjusted to 7 using diluted solution of sodium hydroxide or hydrochloric acid. The culture medium is heated at 121 degrees C for 30 minutes, and then cooled to obtain fermentation culture medium. Synergistic agent (0.2-1.8%) is added to the obtained medium, and then fermented at 25-35 degrees C for 24-48 hours. Light calcium carbonate or white carbon black is added to the fermented material, and then dried to obtain powder, where the water content is less than 5%. The obtained powder is packaged in a container. Additive (0.1-0.5%) is dissolved in water, and then stirred. The obtained composite micro-organism fertilizer master batch is added in the obtained mixture, and then stirred for 20-30 minutes in a stirrer to obtain the desired product.