The embodiment of the invention discloses a moving spraying device which is used for spraying a steel structure and applied to the field of building construction. The moving spraying device of the embodiment comprises a spraying module, a sliding rope, a lifting controller, a transmission module, spraying equipment and a pipeline, wherein the spraying module is mounted on the steel structure and used for spraying the steel structure; the sliding rope is mounted on the steel structure and parallel with the axis of the steel structure; one end of the transmission module is connected with the lifting controller, and the other end of the transmission module is connected with the spraying module, so that the lifting controller controls the movement of the spraying module on the sliding rope through the transmission module; and one end of the pipeline is connected with the spraying module, the other end of the pipeline is connected with the spraying equipment, and the pipeline is used for conveying a paint in the spraying equipment to the spraying module. The moving spraying device can increase spraying construction efficiency, reduce equipment cost and manual cost on spraying construction and avoid the risk that a constructor carries out spraying operation at a high altitude.