Based on the support problem of +708~+750 m large inclination cut with thick coal roof, high pretension bolt anchor supporting technology was put forward. Field measurement result showed that the both sides deformation tended steady after 13 d, the maximum deformation was 185mm and the average deformation was 14.2 mm/d; the roof subsidence tended steady after 10 d, the maximum subsidence was 127mm and the average subsidence was 12.7 mm/d. The supporting technology controlled the deformation of cut and provided protection for supporting transportation and installation.