Drainage of water-related disasters in deep mine can be effectively solved by ultra-high parameter tandem pump drainage system. In light of the hydraulic transition process of ultra-high parameter tandem pump drainage system in mine rescue, numerical model of the hydraulic transition process of ultra-high parameter tandem pump system and the boundary conditions of the pump when the pumping accidents occurred were established. By using the characteristic line method of water hammer calculation in pumping station, the calculation method during the hydraulic transition process of tandem pump system was established, and the hydraulic transition process during the ultra-high parameter tandem pump drainage system in mine rescue when pumping accidents occurred was numerically studied by using FORTRAN language. The results can provide theoretical support for the design and operation of real system, improve the reliability of mine drainage rescue and ensure safe and stable operation of the system.