1: Laser therapy can remove the protruding scar tissue in the scanned area by changing the rejection characteristics of laser. It may be effective to remove the protruding skin, but it is impossible to fill the depressed area. Improper use of laser can also produce new scars or uneven spots. 2. Chemical peeling method: apply chemicals such as carbolic acid, trichloroacetic acid or α-hydroxy acid on the surface of the scar skin to remove the superficial skin cells and wait for the skin at the scar to fall off. But it will change the skin pigment, leading to hypopigmentation, which is not suitable for most yellow people. 3. Inject bovine collagen and add anesthetic into it, inject it into the dermis, let the body "dissolve" collagen and fill the depression. This method is very allergic, and an allergy test must be done before operation, and it can't eliminate the raised scar. 4. Fat injection method obtains fat from another part of the body through surgical liposuction, extracts it and injects it into the scar, trying to make scar fat proliferate and fill the depression, but the survival rate of fat transplantation is low, and many transplants need to cooperate with surgical liposuction, which is risky. 5. Apply the cooling agent to the numb skin of the affected area by physical dermabrasion, and then polish the skin around the sunken scar with a rotatable instrument to make the skin surface smooth, so that the sunken place is not obvious, but it is easy to bleed and make the skin rough; The skin turns black after exposure.