Exterior wall painting device for house building construction

The utility model provides an exterior wall painting device for house building construction, which comprises a support, a limit rod and a moving mechanism, the limit rod and the moving mechanism are arranged at the top of the support, fixing blocks are fixedly mounted at two ends of the limit rod, a servo motor is fixedly mounted at the top of the interior of one fixing block, and an output shaft of the servo motor is fixedly connected with a reciprocating screw rod; the moving mechanism is in threaded engagement with the outer surface of the reciprocating lead screw, and a limiting mechanism used for limiting the spray gun is arranged at the top of the moving mechanism. An output shaft of the servo motor is controlled to rotate through an external power source to drive the reciprocating lead screw to rotate, the moving mechanism slides left and right on the surface of the supporting plate to drive the spray gun to move left and right, and wall painting is achieved; manual painting is replaced by mechanical s