TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Composite Fungicide: The volume ratio of each zymophyte liquid is as follows: 15-35 parts of B. brevis zymophyte liquid, 15-35 parts of P. fluorescens zymophyte liquid, and 20-40 parts of sugarcane thermophilic Actinomyces; preferably 30 parts of B. brevis zymophyte liquid, 30 parts of P. fluorescens zymophyte liquid, and 40 parts of sugarcane thermophilic Actinomyces. The B. brevis in the composite fungicide is separated from the rabbit manure; the P. fluorescens and the sugarcane thermophilic Actinomyces are separated from the cartinellin slag; the preserved numbers of three bacterial strains are as follows: the preserved number of B. brevis is CCTCC NO: M2010133; the preserved number of P. fluorescens is CCTCC NO: M2010135; and the preserved number of sugarcane thermophilic Actinomyces is CCTCC NO: M2010134. Separating method of B. brevis, P. fluorescens and sugarcane thermophilic Actinomyces is as follows: the decomposed rabbit manure and the decomposed cartinellin slag are respectively regarded as the samples for preparing a bacterial suspending liquid; the bacteria strain is separated from the two materials by using a method of diluting the flat plate; the specific method is as follows: 10 g samples are respectively weighed and diluted by sterile water so as to prepare bacterial suspending liquid of 10-1, 10-2, 10-3, 10-4, 10-6 and 10-7 g/mL; 1 ml bacteria suspending liquid with different concentrations and gradients is respectively injected to a petri dish; then, beef extract nutrient medium, potato dextrose agar (PDA) nutrient medium or improved No.1 Gause nutrient medium are respectively dumped to each petri dish for being mixed uniformly so as to prepare a mixed bacteria flat plate; after the nutrient medium is solidified, the flat plate is arranged in an incubator at 45-50 degrees C for being cultivated inversely until the bacterial colony forms; the single bacterial colony is selected and separated, purified and stored on the corresponding flat plate so as to obtain 27 kinds of bacteria by the separation testing step; and then, each bacterial strain is regarded as the single fungicide thrown into the pig manure for being fermented and composted for sieving the effective fungicide suitable for compositing the pig manure so as to obtain three effective bacteria strains: B. brevis, P. fluorescens and sugarcane thermophilic Actinomyces. The composite fungicide is used for composting the pig manure by (a) the pig manure is added with straw so that the C/N mass ratio in the organic matter is 20-30:1; the water content is 50-60%; the pH value is 7-7.5; (b) each 1000 g organic material is added with 50-80 mL zymophyte liquid; the organic material in step (a) is added with composite fungicide and mixed uniformly for composting and fermenting; and (c) the composting temperature rises to 50 degrees C; each 1000 g organic material is added with 20-50 mL composite fungicide according to the proportion of the zymophyte liquid, stirred uniformly, and piled manually every three days until the pig manure is decomposed. Preferred Method: In the method for preparing composite fungicide, the temperature of the incubator in step (a) is 50 degrees C. The sterilizing temperature in step (c) is 121 degrees C.