Biological seed dressing is a cost-effective means to protect plant roots from pathogens.Trichodermais generally considered as one of the most common biological seed dressings. However, there is still a dearth of information on the effects ofTrichodermaon microbial community of rhizosphere soil. High-throughput sequencing was used to analyze the effects ofTrichoderma virideand a chemical fungicide on microbial community of soybean rhizosphere soil. The results showed that bothT. virideand chemical fungicide could significantly reduce the disease index of soybean (15.11% for Trichoderma and 17.33% for Chemical), while no significant difference was observed between them. BothT. virideand chemical fungicide could affect the structure of rhizosphere microbial community, they increased the β-diversity of microbial community and significantly reduce the relative abundance of Saprotroph-Symbiotroph. Chemical fungicide could reduce the complexity and stability of co-occurrence network. However,T. virideis beneficial for maintaining network stability and increasing network complexity. There were 31 bacterial genera and 21 fungal genera significantly correlated with the disease index. Furthermore, several potential plant pathogenic microorganisms were also positively correlated with disease index, such asFusarium,Aspergillus,Conocybe,Naganishia, andMonocillium. From this work,T. viridemay be used as a substitute for chemical fungicide to control soybean root rot and be more friendly to soil microecology.