The utility model relates to a pump for a nuclear power station, and in particular relates to a nuclear secondary pump charging pump of a 1000MW nuclear power station. The nuclear secondary pump charging pump comprises an inner shell body, an outer shell body, a pump head, an end cover, a main shaft, a multistage impeller and a bearing body component, wherein the pump head and the end cover are respectively arranged at two ends of the outer shell body, and the inner shell body is embedded in the outer shell body and is connected with the pump head through a head plate; the main shaft is rotatably arranged in the inner shell body and the outer shell body, a driving side passes through the pump head and is connected with the bearing body component, and the multistage impeller is sleeved on the main shaft and is arranged in the inner shell body; and one side of the pump head is connected with the outer shell body, the other end is provided with a mechanical seal sleeved on the main shaft, and the pump head is symmetrically connected with an absorption flange and a discharge flange. For the pump provided by the utility model, a high-efficiency and advanced hydraulic model is provided, various functions can be realized through the performance requirements of multiple work station points, and the pump has a lift sharp reduction characteristic at a large flow rate point; and the bearing does not need to be lubricated in advance, and the charging pump can be directly and quickly started without prelubrication and reach an excellent effect.