Abstract: In view of the difficulty in selecting mechanical parameters of jointed rock mass, a mechanical model of jointed rock mass considering joint strength is built based on the geological strength index GSI, combined with the damage mechanics principle and the generalized Hoek-Brown criterion, and the stability of deep jointed rock mass working face is analyzed. The results show that the given joint equivalent coefficient can better reflect the relationship between joint spacing and GSI. The stability of jointed rock face is affected by the degree of rock fragmentation. With the increase of rock fragmentation, the working face is prone to roof caving, coal wall spalling and other phenomena. When the rock mass is relatively broken, the instability of the roof is mainly caused by the development of joints. When the integrity of the rock mass is good, the stability of the roof is greatly affected by the suspended part.