In order to study the grouting modification and surrounding rock control technology behind the water rich and sandy layer of a large cross-section inclined shaft, taking the main inclined shaft of Caojiatan Coal Mine as the background, numerical simulation was used to compare and analyze the water inrush and surrounding rock control effects of the sandy layer without grouting and using ordinary Portland cement, cement water glass, and SJP grouting materials for grouting. A reasonable control plan for the surrounding rock of the sand rich layer was proposed. The research results indicate that the deformation, plastic zone range, and permeability of the surrounding rock of the tunnel after grouting are significantly reduced. The surrounding rock control and anti-seepage ability of SJP grouting material are better than those of ordinary Portland cement and cement water glass grouting material. The on-site engineering application shows that after using SJP grouting modification, the water inflow in the sand layer section of the inclined shaft is reduced from 97m3/h to 8m3/h, with a reduction rate of 92%. The overall stress state of the treated section of the wellbore structure is good, and the wellbore structure is basically stable. The use of SJP grouting material for wall grouting effectively ensures the safety and stability of the inclined shaft.