Based on weakening effect of water flooding in underground rock strata on performance of anchor rope and mechanical properties of surrounding rock, typical flooded roadway was taken as engineering background, the failure characteristics of roadway deformation and damage characteristics of support structure ( steel, bolt and anchor cable ) were analyzed, as well as influence of flood water on the nature and support structure of roadway surrounding rocks. Therefore, control mechanism of this kind of roadway was put forward, as well as corresponding support scheme to make engineering practice.