The roof caving of 5-1 coal seam working face in Guojiawan Coal Mine was not timely in the process of mining, and the weighting step was large, which threatened the safety of personnel and equipment in the working face. Therefore, the research on roof cutting and pressure relief technology was carried out in NO.51212 Face. The test of mechanical parameters showed that the uniaxial compressive strength of siltstone was 56.84 MPa, and the RQD value was 93 %, which belonged to a relatively strong and stable rock layer. The caving of this kind of rock stratum lagged behind, and the hanging roof effect was formed in the goaf. The size of the caving step was affected by the uniaxial tensile strength of the roof and the thickness of the rock stratum. Hydraulic fracturing achieved the purpose of reducing the pressure step by indirectly reducing the width of the working face. Combined with the geological conditions of the working face, the roof cutting scheme was determined and applied on site. The results showed that after hydraulic fracturing and roof cutting, the initial mining roof of NO.51212 Face collapsed in time. Compared with the non-cutting working face, the initial weighting step and the periodic weighting step were reduced by 36.1 % and 29.5 % respectively, and the ideal effect was achieved.