Fruit acid can be used to repair sunken scars, which can make skin exfoliate, promote the exfoliation of aged cuticle, accelerate the renewal of keratinocytes and a small number of epithelial cells, and promote the proliferation of elastic fibers in dermis. It has a good curative effect on superficial acne marks and can also improve the coarse pores, but it takes several courses to eliminate acne marks, but its advantages are safety and little side effects. Filling method is used to repair scars. Implants (such as collagen, autologous fat cells) can be injected to raise the concave part and make it flush with the surrounding skin tissue. Pulsed light repair Pulsed light stimulates the proliferation of fibroblasts, making the dermis thicker and the pits flat. At the same time, pulsed light can stimulate the proliferation of collagen.