Collagen rhinoplasty is to elevate the root of the nose by injecting collagen, which is similar to hyaluronic acid, but with higher hardness and viscosity and slightly longer maintenance time, usually lasting two years. This kind of rhinoplasty may cause some complications, and the danger is higher than that of surgical rhinoplasty, as follows: 1, redness and swelling at the injection site: a small number of patients will have local redness and swelling after injection, and it will disappear by itself in about 1-2 days; 2, localized bruising: if the needle accidentally touches the capillaries during the injection process, it is easy for subcutaneous bruising to occur, and most of them will disappear in half a month; 3, inappropriate amount of injections. Inappropriate amount of injection: During the injection process, the doctor does not pinpoint the amount of injection accurately, if the injection is seriously overdosed, the injection needs to be taken out, but it is difficult to take it out. If the amount of injection is not enough, it will lead to poor nasal shape; 4, local infection: if the postoperative care is not appropriate or operation is not strict, it will lead to redness and other infections in the nose. Once the infection occurs, it is necessary to go to the hospital in time for follow-up to deal with it as soon as possible; 5, allergic reaction: collagen injection must be carried out before the skin allergy test, positive people are prohibited from injection. Even if the skin test is negative, allergic symptoms such as edema, nodules, pressure, itching and erythema may still occur; 6. Post-injection embolism: leading to skin necrosis, loss of vision, cerebral infarction and so on.