This research aimed to screen high-efficiency plant rhizosphere growth-promotingstrains，analyze the potential of strains for growth-promoting applications，and provide valuable strain resources for the development of microbial fertilizers. The rhizosphere soil wascollected in Ledong Li Autonomouscounty，Hainanprovince，and the probiotic strains were isolated and screened by dilution coating method to study their ability to produce indoleaceticacid(IAA)，siderophore，proteaseand phosphorussolubilization，and the new isolates were identified to species by 16S rRNA gene phylogenetic analysis and genome characteristics. A strain S03 producing a variety of pro-life substances wasisolated，and the results based on 16S rRNA gene and phylogenetic tree analysis showed that the new isolate S03 was most closely related to NR 157736 Bacillus tropicus1A01406，and combined with the results of genome-wideanalysis，strain S03 was identified as Bacillus tropicus. Strain S03 was 5.42 Mb which was composed of a circular chromosome of 5420614 base pairs without plasmid and with base pairs G+C contentof36.02%，5666 protein -coding sequences. Bacillus tropicus S03 possesses genes related to the synthesisofbiomass(IAA，siderophore，etc.)by comparative analysis of GO database. Bacillus tropicus S03 had good potential topromotegrowth，with IAA yield of 45.73 mg·L -1 and the solubilization capacity of inorganic phosphorus was 82.30 mg·L -1， and it also had the ability to produce protease and iron carriers. Bacillus tropicus S03 bacterial solution could significantly promote the growth of small rapeseed and improve the yield and quality. Bacillus tropicus S03 can dissolve inorganic phosphorus and produce probiotic substances such asIAA，siderophore andproteases，which have good potential for probiotic applications.