Aiming at the problems of surface weathering, water swelling and fragmentation and large deformation of surrounding rock of roadway with extra-thick mudstone roof, the stress situation of surrounding rock of roadway was analyzed by investigating the deformation characteristics, stress environment and strength of surrounding rock. The roof support technology of roadway with full anchor cable was put forward, which could control the deformation of deep surrounding rock by strengthening shallow surrounding rock and sealing the surface of roadway with shotcrete. The underground test showed that the deformation of surrounding rock was effectively controlled and the overall deformation was not large.