The present invention relates to a biocontrol strain against the wilt of continuous cropping cucumber and watermelon as well as its microbial organic fertilizer, which belongs to the technology for agricultural intensive production. The present invention separates Trichoderma harzianum SQR-T037, which has a remarkable biocontrol effect against wilt of cucumber and watermelon. Microbial organic fertilizer was produced from this biocontrol strain and organic compost. In this fertilizer, the content of the strain is above 1 × 10 8 cfu/g, the content of total nitrogen is 3~5% (above 90% of the nitrogen is organic nitrogen), total nitrogen-phosphorus-potassium nutrient is 6~10% and organic matter is 30~35%. As indicated by the experiments, after this microbial organic fertilizer is applied to soil, it will enable rapid multiplication of biocontrol strain into a dominant microflora in the soil and achieve more than 85% of biocontrol rate of wilt in the soil suffering from serious cucumber and watermelon wilt. If this microbial organic fertilizer is applied to the soil without continuous cropping obstacle for a long time, its controlling rate of cucumber and watermelon wilt will be above 80%.
