The invention discloses a microbial agent for promoting aerobic composting of dead pigs and an application of the microbial agent. The microbial agent includes bacillus licheniformis ZR-1, bacillus subtilis dcy-1, bacillus methylotrophicus F7 and bacillus amyloliquefaciens YZ-0001. The microbial agent beneficial to degradation of organic matter is inoculated in the beginning of composting, maximumtemperature of a composting body is increased, high-temperature phase of the composting body is prolonged, pathogenic microbes are inactivated, composting of dead bodies is fastened, degradation of plant toxicity is promoted, and seed germination index is increased; the microbial agent is low in cost, simple in composition, convenient in preparation and easy to promote and apply; the microbial agent of aerobic composting of the dead pigs can generate stable humus and can be used as organic fertilizer applied to crop planting, suppress phytopathogens and reduce use of the fertilizer, and gooddevelopment prospect is achieved.