Abstract In the present study, four Trichoderma species were isolated and made into a biofertilizer. Following treatment with the biofertilizer for 30 days, the germination rate (↑22.5%), height (↑24.4%), fresh weight (↑41.7%), and yield (↑37.4%) of flowering Chinese cabbage increased markedly compared with those of the control. In addition, the contents of soluble sugar (2.044%), soluble protein (5.938 %), and chlorophyll (2.803 mg/g) were higher in flowering Chinese cabbage treated with the biofertilizer for 30 days, compared to the control (1.7.4%, 5.611% and 2.639 mg/g respectively); however, the content of nitric nitrogen, with toxicological consequences for human health, was lower (↓23.6%), indicating that Trichoderma could also improve the quality of flowering Chinese cabbage. After Evans blue and Nitro blue tetrazolium staining, the leaves of flowering Chinese cabbage treated with the biofertilizer showed a smaller blue area than in the control, suggesting that the biofertilizer enhanced the tolerance of flowering Chinese cabbage to environment stresses. Furthermore, the biofertilizer contributed to the increasing of soil enzyme activity at 30th days, including urease (↑25.1%), phosphatase (↑13.1%), and catalase (↑14.0%), providing more inorganic N and P to the soil and reducing the harm done to flowering Chinese cabbage by reactive oxygen species. Taken together, the results showed the Trichoderma biofertilizer enhanced the nutrient uptake and tolerance environment stresses, further improving the quality and production of flowering Chinese cabbage.