Formation of acne pits: scar pits are formed because when acne and acne inflammation are too strong and collagen in dermis is too much, it is possible to leave pits because of the collapse of dermis. Many acne patients like to squeeze acne by hand. If they are squeezed improperly, it will greatly increase the chance of suppurative infection, and it is easy to turn small acne and small acne into big acne, thus leaving scars. Once the pit is created, it will not disappear automatically. Method for repair scar pits with collagen: that method for repair scar pits with bimei collagen is fan injection, because the fan injection technology makes the injected substance radiate in a fan shape at the same pinhole and stabilize at a specific skin level, so the effect is even and accurate, and the effective utilization rate of collagen can be improved to the maximum extent. It is considered as one of the most revolutionary breakthroughs since the birth of non-surgical plastic surgery. This fan-shaped injection technology is especially suitable for injection and filling of collagen. In addition, bimei collagen injection is the safest and most effective part of dermal tissue. The principle of Bimei collagen in repairing scar pits is that collagen plays a supporting role quickly at the injection site, and the connective tissue cells around the implantation site will grow into a collagen network structure, gradually forming a structure similar to normal tissue, stimulating fibroblasts to produce their own collagen, thus ensuring a more lasting effect of collagen injection repair. Postoperative effect of collagen repairing scar pits: Shuangmei collagen can not only instantly fill the pits to repair scars, but also obviously improve skin quality and eliminate various manifestations of skin aging. After bimei collagen is implanted into the skin, the effect is immediate, and it can instantly make the skin return to a youthful state, refreshing, bulging, firm and full.