American cubic plastic experts say that collagen is a filler that can repair facial depressions, facial contours and remove wrinkles. Collagen is one of the most widely used biomedical materials with high safety and biocompatibility. It has been used for facial micro-plastic injection for more than 30 years. Injected collagen rapidly plays a supporting role at the injection site, and 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 that the implantation effect is maintained outside the normal degradation cycle of collagen. Shuangmei 1 collagen is gradually reduced by collagenase in human body, and the effect gradually disappears after about 12- 18 months. The specific maintenance time of collagen varies from person to person, and the effect is different with the difference of flapping skills, implantation depth, implantation site, patient's age and living habits.