Two strains of Bacillus subtilis with growth-promoting function were screened from biogas slurry compost，and the liquid and solid inoculants were developed and prepared.The effects of these inoculants on the growth，yield and quality of scallion plants were analyzed through a field micro-plot experiment.The species diversity of bacteria in the rhizosphere soil of scallion was analyzed by high-throughput sequencing.The results showed that the two strains of Bacillus subtilis BNS1 and BNS2 had the ability of nitrogen fixation，phosphate solubilization，potassium solubilization，IAA production and siderophore production.The two kinds of inoculant effectively promoted the growth of scallion，and the effect of solid inoculant was better.Compared with CK，the plant height，fresh weight，false stem height and false stem diameter of scallion treated with solid inoculant significantly increased by 14.75%，15.50%，15.74% and 24.24%，respectively.The accumulation of nitrogen，phosphorus and potassium increased by 16.18%，35.46% and 33.16%，respectively.The contents of soluble sugar，soluble protein and vitamin C in pseudostem increased by 28.11%，29.03% and 10.89%，respectively.The microbial community structure in rhizosphere soil of scallion was affected by the application of two types of inoculants.The relative abundance of beneficial microorganisms such as Arthrobacter，Sphingomonas，Bacillus，Streptomyces and Pseudomonas was increased.The relative abundance of beneficial microorganisms was significantly correlated with soil environmental factors，in which soil available phosphorus and available potassium were the key factors affecting the composition of rhizosphere microbial community of scallion，and soil available potassium content was significantly positively correlated with the relative abundance of Bacillus flora，indicating that inoculant played a potential role in soil potassium solubilization.The results were helpful to understand the practical application value of Bacillus subtilis，and that would provide theoretical reference and technical guidance for the application of Bacillus subtilis in the high quality and high yield cultivation of cash crops such as scallion.