Abstract: Trichoderma is a biocontrol fungus, which is widely distributed in nature. It can effectively control all kinds of plant soil borne diseases, and promote the good growth of plants. In the process of maize planting, it is prone to maize stem rot, maize root rot and other diseases. Trichoderma can be used for biological control of maize diseases. It is mainly described the feature of Trichoderma, and expounded the specific application of Trichoderma in the biological control of maize diseases. The application mechanism of Trichoderma in the biological control of maize diseases is summarized.