Abstract: To the specific technology problems of determining closed distance coal goaf,stopping line at stope working face under the remaining coal pillars in Mugua coal mine,based on theory of mine pressure and the key strata controlling,the field monitoring method was used to monitor the rock surface displacement of the face return airway,the work resistance of advanced support segment pillar and the changes of hydraulic support working resistance with the working face advancing.Influence scope of advance support pressure and the laws of working face overburden strata-pressure behavior were obtained.Through the mechanics calculation combining with site monitoring method,the stopping line of closed distance coal seam was determined,which had onsite guidance significance for closed distance coal seam safety mining.