Abstract: Taking the gob-side entry retaining by roof cutting（ＧＥＲＲＣ） of working face 22204 of No.1 coal mine of Yungaishan as the engineering background, the determination of key parameters of pre-splitting blasting roof cutting with thick and hard sandstone in the direct roof was studied. The mechanical model of double hole blasting was established, by simulation calculation with CDEM software, a numerical model was established to compare and analyze the deformation characteristics of surrounding rock in the roadway under the schemes of different heights and angles of roof cutting. The results show that roof cutting can effectively reduce the cantilever length of the reserved roadway roof and realize the purpose of pressure relief and roadway protection, and the change of cutting height mainly affects the filling degree of goaf and the thickness of short cantilever beam, and the change of the cutting angle mainly affects the length of the cantilever beam of the roof and the lateral support effect of the gangue on the cantilever beam. There is a reasonable range for the cutting height and cutting angle, which is not the greater the better. Final, the roof cutting height of about 9 m, the roof cutting angle of 15°, and the hole spacing between roof cutting holes of 800 mm were obtained, which was applied in the field successfully. It has important guiding significance and engineering reference value for the application of roof cutting and roadway retaining technology under similar conditions.