In order to explore the influence mechanism of coal pillar in different width section on dynamic behavior of gob-side roadway,in this paper, the relationship between overburden fracture and mining stress field is studied combined with the measured data of middle-deep mine in Ordos rock burst working face in different width section. This study shows that the dynamic load and the concentrated static load released when the hard overlying strata broken are the main reasons for the frequent dynamic behavior of the roadway, the coincidence of concentrated dynamic loading and high static loading in gob-side roadway can avoid by using smaller sections of coal pillars, therefore, the risk of dynamic and static load induced impulsive is reduced. The deformation of surrounding rock in gob-side roadway is more advanced in small coal pillar working face, advance support distance of gob-side entry in small coal pillar working face and pressure relief on the positive side of gob-side entry should be taken seriously.