To address the issue of livestock and poultry manure pollution, exogenous microbial agents were applied to enhance the aerobic composting process, thereby improving the fertilizer treatment and utilization of livestock and poultry manure. Under winter conditions, cattle manure was used as the fermentation substrate, and two different microbial agents were added for aerobic composting. The changes in physicochemical properties, maturity, and microbial community structure of the compost were investigated and analyzed. The results show that the high-temperature phase in both Group A and Group B, which were treated with different microbial agents, lasted for more than 7 days. At the end of composting, the pH, EC (electrical conductivity), C/N ratio, TOC (total organic carbon), and GI (germination index) values of both groups met the maturity requirements for livestock and poultry manure fertilizer. The composting effect of Group A is superior to that of Group B. The microbial agents significantly influence the microbial community structure of the compost. At the bacterial phylum level, Actinobacteria has the highest relative abundance in Group A, while proteobacteria was the most abundant in Group B. At the bacterial genus level, the dominant genus in Group A was uncultured-compost-bacterium, whereas in Group B, it was unclassified_Vicinamibacterales. At the fungal phylum level, the dominant species in both groups were similar, with Ascomycota being the absolutely dominant phylum. At the fungal genus level, Mycothermus was the overwhelmingly dominant genus in Group A, while the dominant genera in Group B were more evenly distributed in terms of relative abundance.