The cementation degree of goaf is the key factor to determine the stability of gob-side entry excavation. In order to ensure the stability of surrounding rock of gob-side entry excavation, the lateral abutment pressure and the stability of surrounding rock of gob-side entry driving under the condition of incomplete cementation and complete cementation of goaf were studied by numerical simulation method. The cementation degree of goaf was tested by borehole peep method and distributed optical fiber test method. The results showed that the vertical stress concentration degree and plastic zone range of surrounding rock of gob-side entry driving were greatly reduced under the condition of complete cementation of goaf compared with the condition of incomplete cementation of goaf, which indicated that the stability of gob-side entry driving could be improved under the condition of good cementation of goaf. The borehole peep showed that the integrity of the small coal pillar was good, and the distributed optical fiber data showws that the overburden rock in the goaf was no longer sinking and deformed, which indicated that the 1682 ( 1 ) goaf was in a state of complete cementation, which ensured the stability during the excavation of the gob-side entry.