Compared with other abiotic stresses, drought stress is a serious causal factor leading to crop yield reduction. Poly-γ-glutamic acid (γ-PGA)，as an environmental friendly biomacromolecule, plays an important role in plant growth and regulation. In this project, we studied the effect of exogenous application of γ-PGA on drought resistance of maize (Zea mays. L) and its mechanism were studied. Drought can significantly inhibit the growth and development of maize, but the exogenous application of γ-PGA can apparently increase the dry weight of maize and the contents of ABA, soluble sugar, proline, and chlorophyll under severe drought stress. RNAseq study found that γ-PGA may enhance drought resistance of maize by affecting the expression of the ABA biosynthesis and ABA signal transduction related genes, photosynthesis-related genes and other stress-responsive genes, which were also demonstrated by RT-PCR and promoter motif analysis. The results of diversity and structure analysis of rhizosphere soil bacterial community showed that γ-PGA could enrich the plant growth promoting bacteria such as Actinobacteria, Chloroflexi, Firmicutes, Alphaproteobacteria and Deltaproteobacteria, so as to improve the drought resistance of maize. This study emphasized the possibility of using γ-PGA to improve crop drought resistance and soil environment under drought condition.