Abstract: Combining with the borehole gas concentration tests for the Sichuan red-bed section of the Chengdu-Gui? yang Railway, this paper analyzes its correlation with the stratum chronology geological structure, and tunnel depth on the basis of data statistics, and puts forward the suggestion to qualitatively and quantitatively divide gas working areas. The results show that the correlation between the tunnel gas concentration and the stratum chronology is not significant in the Sichuan red-bed section of the Chengdu-Guiyang Railway (except coal-bearing strata); geological structure plays a controlling role in gas transport and accumulation; and the positive correlation between the gas concentration and the tunnel depth is significant. According to the above conclusions, it could qualitatively divide the gas working areas according to the geological structure and mapping information collected during the survey stage, and quantitatively divide the gas working areas according to the gas concentration test results. The final categorization of gas working areas can be determined by combining the qualitative and quantitative results.