NOVELTY - The method comprises: mixing concentrated sludge, straw powder and digestion agent and then heating in a high-pressure container with an external source to 110-170 degrees C; maintaining the temperature for 0.5-6 hours; slowly transferring the materials into the container in the heating process to keep the mixture in uniformly mixed state in the digestion process and then continuously stirring to obtain the humus size after the reaction; adding acid into the humus size till the pH value is 4-9; cooling and conditioning the mixture till the pH value is 6-8; and reacting the mixture.    USE - The method is useful for producing biological sludge fertilizer. No biological data given.    ADVANTAGE - The method is capable of safely producing the biological sludge fertilizer without toxicity in an environmentally friendly manner thus reducing the crop disease of the crop root.    DETAILED DESCRIPTION - The method comprises: mixing concentrated sludge, straw powder and digestion agent and then heating in a high-pressure container with an external source to 110-170 degrees C; maintaining the temperature for 0.5-6 hours; slowly transferring the materials into the container in the heating process to keep the mixture in uniformly mixed state in the digestion process and then continuously stirring to obtain the humus size after the reaction; adding acid into the humus size till the pH value is 4-9; cooling and conditioning the mixture till the pH value is 6-8; reacting the mixture to obtain the semi-finished product of organic fertilizer; preparing the biological fertilizer of microbial compound fertilizer by preparing a flat solid panel and a sloped luria-bertani (LB) culture medium and then culturing at 30 degrees C to activate the Bacillus subtilus SF1 and Bacillus subtilus JSB1, culturing the activated strain with an LB culture medium at 30 degrees C in 150 revolution per minute in a small scale to produce the microbial seed liquid, adding the collected microbial seed liquid into a large fermentation tank and culturing at 30 degrees C to aging period so that the Bacillus forms spores, taking 100g/L of wheat bran and soybean meal according to a mass ratio of 10:1 and 2mg/L of magnesium sulfate and then mixing, and sterilizing the mixture using air and then filtering; and preparing the microbial compound biological fertilizer by adding the microbial seed liquid to a volumetric ratio of 1/50 into the cooled humus pulp, uniformly mixing the raw materials and then drying to obtain the particle or powder microbial composite fertilizer and packaging the raw materials after checking that they are qualified. The straw powder comprises corn stalk, wheat straw, straw, bean stalk, sorghum stalk, peanut branches and leaves or fruit tree leaves. A mass ratio of the wet straw to the wet sludge is 1-5:20. The LB culture medium comprises 5g/l of yeast extract, 10g/l of peptone and 10g/l of sodium chloride. The dosage of the digestion medicament is 1-8% of the dry weight of the mixture. The digestion medicament is the mixture composed of the alkali mater and sodium pyrophosphate according to a mass ratio of 3-10:1.