A urea solution pumping system, comprising: a bracket mounted to a lower side of a urea solution tank; a pump unit horizontally disposed at a center of an upper part of the bracket and including a pump suctioning a urea solution to one direction and a motor pumping the urea solution to another direction through a gap between a rotor and a stator of the motor inside the pump and discharging the urea solution to a lower side of the bracket; a pair of thawing units fixedly disposed at both sides of the pump unit on the bracket, the pair of thawing units transferring heat to the urea solution and preventing the urea solution from being frozen; and a sensor unit disposed at one side of one of the thawing units and detecting a level, a temperature, and/or a pressure of the urea solution, wherein the motor includes a rotating shaft rotating together with the rotor so that the urea solution is sucked through one end of the rotating shaft and discharged to another end of the rotating shaft, and the pump unit includes an upper cover disposed at the other end of the rotating shaft, having an outlet at a center thereof corresponding to the rotating shaft, and having a three-phase terminal which supplies power to the stator and is disposed at an external side of the outlet; an outlet adaptor integrally extending from the upper cover toward an opposite side of the rotor and fastened to an upper surface of the bracket to transfer the urea solution to the lower side of the bracket; and a relief valve fastened to the outlet adaptor and maintaining the urea solution at a predetermined pressure or lower, wherein, optionally, the relief valve includes a check ball and an elastic member elastically supporting the check ball, characterized in that the stator includes an exterior stator over-molding surrounding an outer peripheral surface of the stator; and an interior stator over-molding surrounding an inner peripheral surface of the stator, the rotor includes a rotor over-molding surrounding an outer side of the rotor, an adaptor insertion recess, into which the outlet adaptor is inserted, is formed on the bracket, and the urea solution pumping system includes a clip that fixes the outlet adaptor to the adaptor insertion recess in a state where the outlet adaptor is inserted into the adaptor insertion recess. a bracket mounted to a lower side of a urea solution tank; a pump unit horizontally disposed at a center of an upper part of the bracket and including a pump suctioning a urea solution to one direction and a motor pumping the urea solution to another direction through a gap between a rotor and a stator of the motor inside the pump and discharging the urea solution to a lower side of the bracket; a pair of thawing units fixedly disposed at both sides of the pump unit on the bracket, the pair of thawing units transferring heat to the urea solution and preventing the urea solution from being frozen; and a sensor unit disposed at one side of one of the thawing units and detecting a level, a temperature, and/or a pressure of the urea solution, wherein the motor includes a rotating shaft rotating together with the rotor so that the urea solution is sucked through one end of the rotating shaft and discharged to another end of the rotating shaft, and the pump unit includes an upper cover disposed at the other end of the rotating shaft, having an outlet at a center thereof corresponding to the rotating shaft, and having a three-phase terminal which supplies power to the stator and is disposed at an external side of the outlet; an outlet adaptor integrally extending from the upper cover toward an opposite side of the rotor and fastened to an upper surface of the bracket to transfer the urea solution to the lower side of the bracket; and a relief valve fastened to the outlet adaptor and maintaining the urea solution at a predetermined pressure or lower, wherein, optionally, the relief valve includes a check ball and an elastic member elastically supporting the check ball, characterized in that the stator includes an exterior stator over-molding surrounding an outer peripheral surface of the stator; and an interior stator over-molding surrounding an inner peripheral surface of the stator, the rotor includes a rotor over-molding surrounding an outer side of the rotor, an adaptor insertion recess, into which the outlet adaptor is inserted, is formed on the bracket, and the urea solution pumping system includes a clip that fixes the outlet adaptor to the adaptor insertion recess in a state where the outlet adaptor is inserted into the adaptor insertion recess.