Safety system for ensuring safety of nuclear power station

The utility model relates to a safety system for ensuring safety of a nuclear power station, comprising a spraying subsystem that is arranged at the upper part of a containment vessel and conducts spray cooling to the interior of the containment vessel. By arranging the spraying subsystem at the upper part of the containment vessel, after safe accidents happen, the spraying subsystem can conduct spray cooling to the equipment and space in the containment vessel, thus being capable of bringing away the heat in the containment vessel, lowering the pressure in the containment vessel, playing the role of preventing the situation that the pressure in the containment vessel exceeds the designed pressure, and improving the reliability and safety of the nuclear power station. Furthermore, a pit heat-absorption water tank can be used for absorbing the heat from a cold pipe section or a heat pipe section of a pressure vessel and the heat from high-temperature fluid when a main steam pipe breaks in the containment vesse