A fluid channel switching pump comprising: an inlet pipe configured to guide a flow of water; an impeller housing fluidly connected to the inlet pipe to receive water introduced from the inlet pipe, having an impeller built therein, and including a first housing outlet and a second housing outlet formed parallel to a tangential direction of rotation of the impeller; a flow path switch configured to form an internal space, including a first inlet and a second inlet, which communicate with the first housing outlet and the second housing outlet, respectively, and including a first outlet and a second outlet, which communicate with the first inlet and the second inlet, respectively; a diaphragm disposed in the internal space of the flow path switch, configured to separate the first inlet and the second inlet, and configured to separate the first outlet and the second outlet; and a motor connected to the impeller to transmit power, characterized in that the diaphragm is formed as one part, and of an elastic material; is in a shape of a circular plate with a protruding central portion having a gentle curvature, and is pre-formed to maintain the protruding shape of the central portion, wherein the diaphragm is formed continuously while protruding from an outermost portion to the central portion, and the curvature is changed at least once, and wherein the diaphragm is configured such that a protruding direction of the diaphragm is changed by 180° by an external force, wherein a flow path leading to the first housing outlet, the first inlet, and the first outlet is defined as a first flow path, and a flow path leading to the second housing outlet, the second inlet, and the second outlet is defined as a second flow path; wherein when the diaphragm maintains a protruding state in one direction, the diaphragm is configured such that either side of the first flow path or the second flow path is closed and the other side is open, wherein the first housing outlet and the second housing outlet extend in a same direction, and wherein, when viewed from a first direction, the flow path switch is in a mortar shape whose width narrows gradually in a second direction perpendicular to the first direction and then widens again at a middle portion. an inlet pipe configured to guide a flow of water; an impeller housing fluidly connected to the inlet pipe to receive water introduced from the inlet pipe, having an impeller built therein, and including a first housing outlet and a second housing outlet formed parallel to a tangential direction of rotation of the impeller; a flow path switch configured to form an internal space, including a first inlet and a second inlet, which communicate with the first housing outlet and the second housing outlet, respectively, and including a first outlet and a second outlet, which communicate with the first inlet and the second inlet, respectively; a diaphragm disposed in the internal space of the flow path switch, configured to separate the first inlet and the second inlet, and configured to separate the first outlet and the second outlet; and a motor connected to the impeller to transmit power, characterized in that the diaphragm is formed as one part, and of an elastic material; is in a shape of a circular plate with a protruding central portion having a gentle curvature, and is pre-formed to maintain the protruding shape of the central portion, wherein the diaphragm is formed continuously while protruding from an outermost portion to the central portion, and the curvature is changed at least once, and wherein the diaphragm is configured such that a protruding direction of the diaphragm is changed by 180° by an external force, wherein a flow path leading to the first housing outlet, the first inlet, and the first outlet is defined as a first flow path, and a flow path leading to the second housing outlet, the second inlet, and the second outlet is defined as a second flow path; wherein when the diaphragm maintains a protruding state in one direction, the diaphragm is configured such that either side of the first flow path or the second flow path is closed and the other side is open, wherein the first housing outlet and the second housing outlet extend in a same direction, and wherein, when viewed from a first direction, the flow path switch is in a mortar shape whose width narrows gradually in a second direction perpendicular to the first direction and then widens again at a middle portion.