Abstract: Summing up advantages and disadvantages of methods for determining pillar width,such as experience method,theoretical calculation method,numerical simulation,field measurement,it is indicated that the pillar width can be determined with the method combining field measurements and numerical simulation.According to actual production of Shitanjing second mine,the regularity of the stress and displacement of the roadway excavat-ing under different coal pillar are analyzed by numerical simulation and field measurement.Through analyzing the monitored data,the relationship among the roadway stability,the strength of bolt support and the pillar width is studied.The reasonable pillar width in Shitanjing second mine is proposed.