The invention provides a shaftless pump and a using method thereof. The shaftless pump comprises an outer ring, a middle ring, an inner ring, a plurality of arc-shaped blades, a plurality of support rods and guide cones, wherein circular bayonets are symmetrically formed in the upper part and the lower part of the outer ring; a U-shaped motor driving coil is arranged on the inner side of the middle ring and serves as a stator; the outer side of the middle ring is hinged to the circular bayonets of the outer ring through two cylindrical hinged pieces, and the outer side of the inner ring is connected with the middle ring through a positioning bearing and serves as a rotor; one end of each support rod is connected with the inner side wall of the inner ring, and the other end of each supportrod is connected with the corresponding guide cone in a supporting mode; the guide cones are positioned in the center of the inner ring; and the arc blades are connected to the middle parts of the corresponding support rods and are uniformly distributed to form an impeller. According to the shaftless pump, an internal middle ring and inner ring linking body of a rotary pump realizes blade expanding while running through a pipeline and operating a water pump; the blade is packed up when the water pump is closed or subjected to fault, so that the flushing of running water on the blade is reduced, and the service life is prolonged.