Tunnel system suitable for karst area

The utility model provides a tunnel system suitable for a karst area. The tunnel system comprises a tunnel main hole adjacent to a karst channel. A drainage main hole is formed below the tunnel main hole, and a drainage transverse hole group and a drainage hole group are formed between the drainage main hole and the karst channel; the drainage transverse hole group comprises at least one drainage transverse hole, and the drainage hole group comprises at least one drainage hole; a water inlet of the drainage hole is communicated with the karst channel; water outlets of the water drainage holes are communicated with water inlets of the water drainage transverse holes, and each water drainage transverse hole is communicated with at least one water drainage hole; a water outlet of the drainage transverse hole is communicated with a water inlet of the drainage main hole; a water inlet of the drainage hole is higher than a water inlet of the drainage transverse hole, and a water inlet of the drainage transverse hol