Abstract: In view of problem of floor heave failure in coal seam roadway, taking 53082 roadway of a mine as the research object, the stress state, displacement distribution and failure form of surrounding rock during the roadway excavation were analyzed and studied by UDEC discrete element simulation software. The results show that under relatively large horizontal tectonic stress, the weak coal seam of roadway floor 53082 becomes the main area of stress release, and the main failure characteristics are shallow tensile failure and deep shear failure. In view of problem that the original support scheme of roadway 53082 can not control the floor displacement and causes serious floor heave, a combined support mode of floor grouting and anchor bolt and cable was put forward through simulation analysis of support effect of different floor support schemes. The test results show that the combined support mode of floor grouting and anchor bolt and cable is superior to the single support mode of anchor bolt and cable, and greatly improves stress state of floor, and restrains the shear failure of deep floor, the displacement of roof and floor is controlled within 150 mm, the displacement of two sides is controlled within 60 mm, and the control effect of surrounding rock of roadway is better.