Abstract:In order to solve a series of problems such as serious roof leakage and rib spalling, poor support effect, low tunneling efficiency and restricted mining progress in the roadway under the coal roof of extremely soft and fragile thick coal seam, the outer section of 842 air roadway in Wobei Coal Mine is taken as the research object. Based on the investigation of its engineering geological conditions and the deformation of roadway under the original support mode, the full-length anchorage technology of prestressed anchor cable in loose coal body is put forward, which is expected to further improve the tunneling level of fully mechanized caving face in extremely soft and fragile thick coal seam in China.