Abstract: The roof of a large section of coal roadway is soft and broken, and it prone to the separation expansion to cause the structural damage of the supporting body, which leads to the outburst accident in turn. In this paper, take the large area collapse during roof tunneling of sectional transportation roadway in 20322 fully mechanized caving face as the research background, through the analysis of the pressure phenomenon before the roof caving, the main reason for the instability of roof structure is that the ground mass fracture and anchor cable parameters are unreasonable. The supporting idea of controlling the soft thick coal roof by adjusting the supporting parameters of the anchor cable to enhance the integrity and resistance strength of the roof support structure is proposed, and it has achieved good results in industrial practice.