Long-span hydropower station underground power house

The utility model relates to a building structure and provides a long-span hydropower station underground power house, which comprises vertical columns and a ring beam consisting of beams. The ring beam is arranged at the tops of the vertical columns; a group of arch beams is arranged between the beams on two opposite sides of the ring beam; an arch slab covering the top of the whole power house is arranged above each arch beam; the arc of each arch slab adapts to that of each arch beam; each arch slab is supported by the corresponding arch beam and the beams on two sides; the arch slabs and the arch beams are in combined slab structures made of profiling steel formworks; and air inlets and return air inlets for communicating an upper space with a lower space of each arch slab are arranged on each arch slab. As the profiling steel formworks are adopted, construction speed is high. Moreover, the profiling steel formworks are used as not only formworks but also tensile reinforcement for the bottom surface of a cast-in-situ structure, and function in decoration. By the aid of the all reinforced concrete structure, the long-span hydropower station underground power house is simple and convenient in maintenance, integrally close, fine in heat insulation and moisture-proof effects, capable of meeting use requirements and avoiding the problem of vibration noise, and applicable to serving as a hydropower station underground power house.