Fractional laser has some improvement effect on depressed scars, but the main role of scar remodeling; clinically plasma is more effective in the treatment of depressed scars. The thermal effect of fractional laser will make uniform micro-holes on the skin, causing a certain degree of minimally invasive thermal damage, stimulating collagen proliferation and collagen fiber rearrangement in the dermis at the depressed scars, and improving the degree of depression of the scars visually. Avoid water for a short period of time after treatment (3 to 5 days) to avoid infection; avoid spicy and stimulating foods; strengthen nursing care and strict sun protection measures, etc. The principle of plasma treatment for depressed scars is mainly the following two: one is that it can peel off the epidermis and restart the skin re-repair mechanism; the other is that the thermal effect produced by the ionic monopole can stimulate the regeneration and rearrangement of fibroblasts. Clinical effect observation to see the effect is better than fractional laser. Fractional laser treatment of depressed scars has a certain effect, multiple treatments to achieve the desired results; it is recommended to the regular medical institutions to comply with the recommendations of specialists to choose the appropriate treatment plan, and to do a good job of post-treatment care, to avoid the occurrence of infection, scarring, allergies and other adverse reactions.