This research was carried out to screen saline-alkali-tolerant Bacillus sp. producing polyglutamic acid and explore the improvement effect of its fermentation broth on plants and Pisha sandstone soil，enrich the theory of soil improvement by microorganisms，and promote the development of microbial ecology. Taking salt tolerance，alkali tolerance and polyglutamic acid yield as screening indexes，Bacillus was screened from existing soil samples in the laboratory. A pot experiment was conducted to evaluate the effects of strains on ryegrass growth and Pisha sandstone soil fertility by analyzing ryegrass biomass，soil water retention，water permeability，enzyme activity，soil pH，cation exchange capacity，organic matter，available phosphorus，available potassium and polysaccharide content. Two strains of saline-alkali-tolerant strain YF20 and YG35 with high polyglutamic acid production were screened，which belonged to Bacillus zanthoxyli and Priestia megaterium respectively. Strain YG35 significantly increased the fresh weight of ryegrass by 33%，soil polysaccharide content by 40%，organic matter content by 23%，available phosphorus content by 31%，and sucrase activity by 17% than biochar，respectively. Strain YF20 significantly increased soil cation exchange capacity by 7.2%，organic matter by 15%，water retention rate by 2.2%，and water permeability by 2.74% than biochar，respectively. Two strains of polyglutamic acid producing bacteria can improve the quality of Pisha sandstone soil and promote plant growth，which provides a theoretical basis for microbial improvement of Pisha sandstone soil.