Abstract： In view of the large deformation of weakly cemented soft rock roadway in Dananhu No.7 coal mine under alkaline water environment, the deformation mechanism of weakly cemented soft rock roadway surrounding rock under alkaline water erosion was studied by means of field measurement and numerical calculation, the evolution of plastic zone of roadway surrounding rock under different support parameters and the bearing characteristics of anchor rods and ropes were analyzed, and the best support scheme for weakly cemented soft rock roadway was proposed. The results show that under the existing support parameters, the overall shifting amount of the roadway and the anchor rods and ropes bearing tend to increase sharply first and then slowly, and the shallow delamination phenomenon is obvious; the weakly cemented soft rock roadway with rich alkaline water has the characteristics of rapid initial deformation and large shallow delamination, timely support measures should be taken; the anchor rod and anchor rope row distance is the main control factor of the deformation of the surrounding rock and the anchor rod and rope loading value of the roadway; the proposed and verified anchor rod pre-stress of 50N, anchor length The support scheme of anchor pre-stress 50N, anchor length 1.5m, anchor rod row distance 750mm and anchor cable row distance 1500mm is proposed and verified, and the long-time stability of the roadway is achieved.