The utility model discloses a circulating water pump, including the water pump volute, be located impeller and transmission shaft in the water pump volute, the impeller cover is established on the transmission shaft and fixed connection, and be used for the drive the motor of transmission shaft, two cylinders that the both sides centering includes the symmetric distribution in proper order, symmetric distribution, diameter from both sides centering two crescent horn mouths are followed to the impeller to and vane wheel, the face of cylinder with it is sealed through the sealing ring between the water pump volute, the horn mouth with leave the clearance between the water pump volute, vane wheel is last to form a plurality of blades. The utility model provides a circulating water pump's pump capacity is great, and circulating water system's efficiency is higher, has obtained better energy -conserving effect.