From the anatomical structure of female pelvic floor, vagina is mainly composed of sphincter and related ligaments. When a woman gives birth, the pelvic bone opens and the fetus is born from the birth canal, which will tear and damage the sphincter around the vagina. Postpartum sphincter injury can not be effectively recovered, resulting in weakness of sphincter around vagina, which in turn increases the gap of vaginal cavity and relaxes vulva orifice. Long-term vaginal relaxation is easy to infect all kinds of bacteria, which will lead to some gynecological diseases. At the same time, vaginal relaxation can also cause poor quality of sexual life of couples. At present, vaginal relaxation can be improved and treated by surgery or exercise. Minimally invasive 3D biological belt tightening of private parts is mainly aimed at patients with mild to moderate relaxation, which can tighten vaginal cavity and vaginal orifice. 3-D biological band private tightening is mainly to implant HADM regenerative tissue biological band in the posterior vaginal sphincter and vaginal orifice, to establish ligaments for the relaxed sphincter and vaginal orifice, restore sphincter elasticity and enhance muscle strength, so as to achieve effective vaginal tightening. If it is more than severe relaxation, traditional posterior wall compression surgery can be used for compression. It takes 2-3 months to recover from the operation.