The invention provides a room type cleaning and protecting device used for keeping expanding welding of a heat exchange pipe and a pipe plate of a heat exchanger clean. The cleaning and protecting device is in the shape of a box body; the box body comprises a top face (1), a bottom face (2) and side walls (3); the front wall of the box body is provided with a pipe plate door (4); and one side wall of the box body is provided with a person passing door (5). The invention further provides a method for connecting the heat exchange pipe with the pipe plate through the room type cleaning and protecting device. The room type cleaning and protecting device is simple and reliable in structure, capable of being repeatedly used, wide in application range, free of special using environment and work condition requirements, capable of making operation of arrangement of a clean environment easy, obvious in cleaning effect, free of consumption and losses in the using process and low in manufacturing and using cost.