Abstract: Depended on the belt conveyer lane in Wen Jiapo coal, the floor heave mechanics of large section soft rock roadway was researched by the method of theoretical analysis and lab experiment. Besides, the type of floor heave was determined as hydro-expansiveness.The floor heave support program was put forward and the supporting parameters were given in the article. With the FLAC numerical simulation, the feasibility of floor heave support program which put forward in the paper was verified. The result of industrial test indicated that the floor heave value was 22.4 mm, which was less than the value before floor heave treatment. The floor deformation was so controlled effectively that it met the deformation require of mine block. More importantly, the research results had important reference value to the similar projects.