Concave-convex scars can be treated with erbium laser instrument, and the treatment effect is good. Erbium laser uses epidermal blasting to eliminate hypertrophic scars, and the epidermis is blasted to make the skin grow again. After treatment, the skin epidermis is like a scratch, and it is safe and effective because there is no scar after treatment. The latest Er laser scar tattoo therapeutic instrument introduced by tongji hospital, Shaanxi Province, has obvious repair effect for all kinds of scars, leaving no scars after treatment, which is safe and trustworthy.