Abstract: The large-scale open-pit mining in Inner Mongolia seriously affects the ecological diversity and ecological stability of Inner Mongolia grassland. Due to mining,metal smelting,and the exposure of heavy metal in soil,the heavy metals enter into soil and water environment with atmosphere and water flow. Thus,in the mining area and nearby,the heavy metal pollution is very serious,has seriously affected human food chain and human health. There is a huge chal- lenge in heavy metal pollution control in China. In order to provide a theoretical basis for the microbial remediation of grassland ecological restoration,and screen out highly efficient heavy metal-tolerant strains in open pit mines,taking Baorixile open-pit coal mine area as the research area,a total of five sample sites inside and outside the mine area were selected,and the bacteria resistant to copper ion,iron ion,chromium ion and manganese ion were screened out by using different types of heavy metal stress medium for gradient cultivation,and the strains with the strongest tolerance of each heavy metal were screened out. The results showed that the highest iron concentration of strain XFe-1 was 500 mg / L,the highest copper tolerance of strain XCu-1 was 500 mg / L,and the highest chromium tolerance of strain XCr -1 was 200 mg / L,the highest manganese tolerance of strain XMn-1 is 50 g / L,with the stress of different heavy metal concentration gradients. Then,the growth curve of heavy metal stress was tested on four strains. Four excellent heavy metal-tolerant bacteria were identified by 16s rDNA gene sequence analysis. XFe-1 is Bacillus toyonensis,XCu-1 is Bacillus cereus,and XCr-1 is Brevibacterium sp. ,the XMn-1 and Genbank gene bank sequence alignment and the highest similarity of Bacillus are only 85. 37% ,which is unknown species. The strain resistant to heavy metal was pre- served.