Abstract: According to the geological conditions of horsehead surrounding rock of maiduoshan coal mine and the roadway deformation law after excavated，the mechanical characteristic of surrounding rock is studied，with some supporting problems exposed. In the light of the damaged feature of horsehead floor，it is considered that the floor heave is caused by floor strata curve，squeezed by the both sides of roadway，especially when it encounters with water. Based on the mechanism of and reasons for floor heave，some reinforcement measures including inverted-arch，floor bolt and bottom angle anchor，and floor grouting of surrounding rocks are taken to control the floor deformation. The on-site tests indicates that the floor deformation is effectively controlled through the measures above.

Key words: Horsehead, Floor heave mechnanism, Roadway supporting, Numerical simulation