Trauma dressing change is a change of gauze and possibly dressing on the surface of the wound. Because generally speaking, the wound needs to be changed once in 2-3 days, because after a long time the gauze on the surface of the wound may become dirty, and may be contaminated with bacteria. If the wound has oozing, exudate, gauze wet to be changed in a timely manner, first open the gauze after observing the healing of the wound, whether there is redness, swelling, hard knots, as well as pus, wound infection and other conditions. If the surface color of the wound is normal and there is no wound infection, disinfect the wound twice with iodophor, the range is 3-5cm, and after disinfection, dress the wound again with gauze or dressing.