There are many kinds of treatment methods for depressed scar after acne, such as laser therapy, tissue filling, micro-needle therapy, radio frequency, etc. Non-exfoliating lattice laser and exfoliating lattice laser are still the main treatment methods for depressed scar after acne. However, due to the incidence of adverse reactions, pain during treatment and long downtime, some patients are afraid of treatment and make acne scar light. Electrical therapy is limited. Although non-laser surgery can alleviate the above problems, it is difficult to achieve the desired effect. In recent years, with the development of medical technology and technology, laser technology has developed rapidly and become more mature. Many breakthroughs have been achieved in the treatment of acne scar, which brings new hope to patients.