Large-span underground cavern top arch surrounding rock stability control device

The utility model provides a long-span underground cavern top arch surrounding rock stability control device. The long-span underground cavern top arch surrounding rock stability control device comprises a drainage structure, a primary supporting structure and a secondary supporting structure, wherein the drainage structure is arranged around an underground cavern in advance before the underground cavern is excavated, the primary supporting structure is arranged in the forming process of an underground cavern top arch, and the secondary supporting structure is arranged after the underground cavern top arch is formed. The drainage structure comprises a drainage hole, a drainage gallery and a drainage hole curtain; the anchoring structure comprises opposite penetrating anchor cables. The drainage holes are formed in the upper portion of the top arch surrounding rock of the underground cavern, and the multiple drainage holes are distributed in the upper portion of the underground cavern; the drainage galleries a