The present invention relates to the antagonistic bacteria that are used to prevent and eliminate tobacco bacterial wilt and their microbial organic fertilizer, which belong to the technology for agricultural intensive production. The present invention separates two antagonistic bacteria (Brevibacillus brevis NJL-25 and Bacillus cereus NJL-14) that have remarkable antagonistic action against the pathogens of tobacco bacterial wilt. Microbial organic fertilizer is produced from these antagonistic bacteria and organic compost. Wherein, the content of each of NJL-25 and NJL-14 is above 1×1010 cfu/g, the content of total nitrogen is 4˜5% (above 90% of the nitrogen is organic nitrogen), the content of total nitrogen-phosphorus-kalium nutrient is 6˜10% and the content of organic matter is 30˜35%. As indicated by experiments, after the microbial organic fertilizer is applied into soil, it will enable rapid multiplication of the antagonistic bacteria into a dominant microflora in the soil and achieve more than 97.6% of biocontrol rate of tobacco bacterial wilt in the soil suffering from tobacco bacterial wilt. If the microbial organic fertilizer is applied in the soil without continuous cropping obstacle in a long time, it can prevent the occurrence of the bacterial wilt of continuous cropping tobacco to a great extent.