The fecula produced by the black soldier fly is rich in the nutrients essential for the growth of a variety of plants，which is considered as an ideal raw material for organic fertilizer. However，the high salt content of the black soldier fly fecula limits its application in agriculture. In this study，organic fertilizer that met the current standard was made with the black soldier fly fecula，earthworm dung and straw. The differences between the microbial community composition of organic fertilizer，the black soldier fly fecula and earthworm dung were compared，and the organic fertilizer was used to carry out a pot experiment on the soil improvement. The conductivity of organic fertilizers produced by desalination and composting was significantly lower than that of insect sand，and the germination index of seeds was significantly increased by 31.67%，compared to insect sand. The application of organic fertilizer improved the sugar content of tomato fruit，reduced the number of Fusarium oxysporum in the soil，reduced the risk of tomato blight，and improved the relative abundance of microorganisms in soil Sordariomycetes，Rhizobiales and Chitinophagales. This study provided a feasible scheme for the disposal and utilization of the black soldier fly fecula，which could contribute to the promotion of the restaurant-kitchen waste degradation process and solve the soil problems of the existing facility agriculture.