The invention provides an eddy-eliminating device for removable type pump sump comprising an upper cover plate and a lower cover plate installed on an inlet water pipeline of the pump in the sump. The inlet water pipeline of the pump is composed of an inlet water pipe and an inlet bell mouth fixed on the end of the inlet water pipe. The center of the upper cover plate is provided with a round hole and the upper cover plate is sleeved and fixed on the inlet water pipeline of the pump through the round hole. The internal diameter of the round hole is matched with the external diameter of the fixing place of the inlet water pipeline of the pump on the upper cover plate. The lower cover plate hangs and fixes on the below of the inlet bell mouth. The upper cover plate and the lower cover plate are both horizontally disposed. The eddy-eliminating device has the advantages of moving according to the moving of the inlet water pipeline of the pump, being rational in structure, easy to manufacture, convenient to use and the flow pattern of the inlet bell mouth of inlet water pipeline of the pump is greatly improved. With the current becoming uniform, surface eddies and bottom eddies can be effectively prevented.