The invention relates to two ralstonia-solanacearum-resistant endophytic bacillus velezensis strains and application thereof. By separation, screening and purification in roots of healthy tobacco plants in a ralstonia solanacearum occurrence area of the Enshi Prefecture, two biocontrol bacillus endophyticus strains R-3 and R-9 are obtained, have evident resistance effects on ralstonia solanacearumand are both capable of generating high-temperature-resistant ralstonia-solanacearum-resistant substances. By gyrB gene sequence identification and phylogenetic tree construction, results show that the R-3 and R-9 are both bacillus velezensis; by potted plant root irrigation experimental verification, the bacilli R-3 and R-9 have great colonization performance in tobacco roots and can enter stemsthrough root transmission; by field experimental verification, bacillus velezensis R-3 and R-9 are effective in ralstonia solanacearum prevention and treatment, remarkably superior to chemical agentkasugamycin and free of pollution. The biocontrol endophyte research field is further enriched by researching on the bacilli R-3 and R-9, and a guiding significance to ralstonia solanacearum prevention and treatment is achieved.