Incorporating fruit tree branches into tobacco waste and cattle manure compost piles at appropriate ratios can improve the physicochemical properties of the co-composting materials，create an environment conducive to the growth of aerobic composting microorganisms. It is one of the methods to solve the technical bottleneck of waste recycling. To determine the physical and chemical properties of tobacco waste and fruit tree branch compost，reveal the diversity patterns of bacteria and fungi after aerobic composting，and assess the feasibility of co-composting tobacco waste and fruit tree branches，100 kilograms of fresh tobacco samples and 100 kilograms of fresh cattle manure were mixed in laboratory containers under four treatments:no addition of fruit tree branches(T0)，10% fruit tree branches(T1)，20% fruit tree branches(T2)，and 30% fruit tree branches(T3). The compost pile temperature and nicotine content were monitored，and after the composting process，the germination index and the taxonomic composition of bacteria and fungi were analyzed to understand the characteristics of the composting process under different treatments. The results showed that after adding fruit tree branches，the time required for the compost pile to reach high temperatures was extended，with T1，T2，and T3 extending by 3，4，and 5 d，respectively. The high-temperature period was shortened，with T1，T2，and T3 reducing by 5，9，and 9 d，respectively. There was no significant difference in the time to reach ambient temperature. As the proportion of fruit tree branches in the compost pile increased，the germination index became higher. After 60 d of aerobic composting，the nicotine content in all treatments met environmental standards. On the 60th day of composting，the nicotine content in T3 was significantly lower than in T0，T1，and T2(P<0.05)，and the nicotine content in T2 was also significantly lower than T0 and T1(P<0.05). After adding fruit tree branches，the bacterial community mainly increased the relative abundance of the Firmicutes and decreased the relative abundance of the Actinobacteria，while the fungal community decreased the relative abundance of the Ascomycota. The community samples of T0 and T1，as well as T2 and T3，were similar. Adding 20%–30% fruit tree branches to the tobacco waste pile significantly changed the species diversity of the microbial community in the pile. Adding 10%–30% fruit tree branches to tobacco waste and cow manure compost could improve the efficiency and maturity of the compost，showing great application prospects.