Gob-side entry set is the important way to improve resource recovery and optimize working face settlement, based on the instability of gob side entry problem, 5207 working face god-side entry of some mine in Shanxi was taken as example, the instability of gob-side entry was analyzed as 3 categories like cut roof instability, return instability and broken instability, based on this, means that improving gob-side entry stability was expounded. Through numerical study, the coal column and support structure were crucial to 5207 working face gob-side entry stability, the best coal column of the gob side entry was set as 6 m, necessary support structure was applied based on this.