The purpose of this study was to understand the effects of continuous cropping of forage maize on the diversity of soil culturable bacteria resources and the growth-promoting bacteria，which were obtained from the soil with 7 consecutive years of maize planting in Gansu and comprehensively analyzed.In this study，the culturable bacteria were isolated using eutrophic medium (NA) and selective medium (Ashby)，and 16S rRNA gene sequencing and comparative analysis were performed on the obtained strains，the ability of producing plant growth hormone (IAA)，dissolving phosphorus and fixing nitrogen was evaluated.A total of 224 strains of bacteria were isolated from soil of different continuous cropping years.The results of functional evaluation of microbial strains showed that 34 strains had the IAA production ability，25 strains had the organic phosphorus dissolving ability 19 strains had the inorganic phosphorus dissolving ability，27 strains showed high nitrogenase activity，and 5 strains had both IAA production and phosphorus dissolving ability.The results of information analysis of culturable microorganisms showed that the bacterial richness and diversity of soil under maize cultivation and fertile strains increased with the increase of continuous cropping years.The dominant genus of culturable bacteria was Pseudomonas，which was widely distributed in the soil with different continuous cropping years and showed excellent ability of producing IAA，dissolved organic phosphorus，inorganic phosphorus and nitrogen fixation.This study shows that 7-year continuous cropping of maize can significantly affect the structure of soil flora，and the soil contains abundant resources of growth-promoting bacteria.The isolated functional strains can provide information for the development of microbial fertilizer suitable for production of green maize and growth-promoting strains support in Gansu Province.