Abstract: Aiming at the supporting difficulty of 7.5 m×3.3 m large-section open-off cut in first mining fully mechanized caving face at -960 m level of one domestic coal mine, on the basis of the analysis of supporting difficulty, the study decided to adopt high strength support system and the construction method of wide guide narrow expansion, selected new support materials with high strength, high stiffness, high reliability and big elongation, conducted the support design, determined the reasonable supporting parameters. The results of practical application and mine pressure monitoring show that this scheme can effectively control the deformation and failure of roadway and achieve a good supporting effect.