Abstract: In response to the support problem under high stress in long-span roadway, taking the 7801 open-off cut in Wuyang mine as the engineering case, the microfracture development, stress distribution and deformation, failure and collapse laws have been researched in surrounding rock of long-span roadway under different side pressure coefficient and buried depths. The reducing-span support technology consisting of “reasonable section shape of secondary tunneling, bolt-mesh-cable, steel strip and hydraulic single prop” has been put forward. In the meanwhile, the long-span support parameters of open-off cut have been improved. The research shows that the original support scheme can not effectively control the deformation of roadway surrounding rock when the buried depth of 7801 open-off cut is more than 600 m; while the new reducing-span support technology can effectively control the deformation of surrounding rock, when the maximum for the roof-to-floor convergence, rib-to-rib convergence, roof separation and working resistance of single prop all in control are 55.5 mm，25.1 mm，24.8 mm and 12.52 MPa respectively. The researches effectively solve the support problem of 7801 open-off cut in Wuyang mine and provide reference for support design of long-span roadway.

Key words: long-span roadway, roof collapse laws, reducing-span support, double flat arched section