In order to study the stability of complex mud roof of coal roadway under the mining pressure, example of the working surface 20307 in Gao Jialiang Coal Mine is presented. Based on the analysis of rocks microstructure characteristics and measurement of surrounding rock loose circle by hole examining method, the complex mud roof of coal roadway is the geological soft rock which is a complex type of stress dilatancy expansion. The mechanisms of roadway damage are complex deformation mechanisms includingⅠ_ABⅡ_BDⅢ_DA, and the bolt-mesh-cable-grout with steel band coupling support design is proposed, which adopts the finite difference program FLAC^3D to simulate the stability of complex mud roof of coal roadway with coupling support; Then it also adopts the in-situ investigation to perform field monitoring for the deformation of coal roadway, and the comparative analysis between numerical analysis and field monitoring is studied. The results reveal that stability of complex mud roof of coal roadway is effectively in control under the mining pressure, which consequently verifies the validity of deformation and damage mechanisms of complex type of stress dilatancy expansion and the effectiveness of coupling support proposed in this paper, meanwhile it also provides the reference to the similar engineering geologic condition of coal roadway.