Abstract: The application effect of traditional support technology in the soft rock leaching roadway in the of Sanyuan Grottoes Coal mine is not good. The tunnel roof support technology is improved by grouting blocking and anchor cable support technology. Based on the FLAC3D numerical simulation software, the distribution characteristics of the deformation and the maximum principal stress of the surrounding rock of the anchor cable hole under the conditions of 1, 5, 10 MPa grouting pressure and 300, 400, 500 mm sealing length were analyzed. The mechanical properties of the support were tested by drawing test in underground, and the industrial test was carried out. The results show that the displacement of surrounding rock of anchor cable hole increases with the increase of slurry pressure. The grouting pressure under soft siltstone condition should not be greater than 5 MPa. The sealing length should be based on the location of crack development in surrounding rock. When the crack development location is in the deep area of surrounding rock, the sealing length should be relatively long, and vice versa. The increase of sealing length is beneficial to improve the tensile strength of anchor cable. After 50 days of grouting and cable support, the deformation of surrounding rock is basically stable, and the phenomenon of water leaching is greatly reduced.