Skin soft tissue expansion refers to the expansion of the skin soft tissue of a new technology, in recent years has been widely used in cosmetic plastic surgery. In the past, the plastic repair of skin scars and tissue defects mainly relied on autologous tissue transplantation, so some people say that plastic surgery is “tearing down the east wall to make up for the west wall”. For smaller skin lesions can be used once the excision or sub-suture shrinkage method, the surgical effect is more ideal; but a little larger, especially the face, head and other larger can only be used to implant the method. Although skin grafting has the effect of improving the appearance, but due to a series of problems such as skin color, skin edge scars after skin grafting, even if the skin grafts survive well, it will not bring much change to the facial beauty. Skin flaps and skin tube transfers are used to repair lesions with good results, but the limited source of skin flaps restricts the scope of their application. The cosmetic principle of the soft skin tissue expander is to provide “extra” soft skin tissue. The dilator is a capsule made of a silicone rubber membrane, and the commonly used type consists of a dilator capsule, an injection pot, and a catheter. The dilator is surgically implanted under the skin, and sterile isotonic saline is periodically injected through the skin into the injection pot, which flows down the catheter into the dilatation capsule to dilate the tissue. After a certain period of time, the skin and soft tissues on the surface of the capsule are gradually stretched and expanded, providing approximately 50% or more “extra” skin tissue, or creating a gap in the tissue to accommodate a bone implant or a prosthetic implant. Tissue expanders are mainly used in the face, neck, head, breasts, trunk and limbs where normal skin is required for cosmetic restoration. The advantage is that the “extra” skin tissue provided by the tissue expander is similar to or consistent with the surrounding skin of the defect area in terms of color, texture, thickness, hair distribution and aesthetics, and has the advantages of good blood flow and sensation. It also has the characteristics of good blood circulation and sensation, and does not produce new scars in the skin donor area as in the case of skin grafting. Therefore, it has the incomparable advantages of traditional plastic surgery treatment methods. This epoch-making great creation is the same as the invention or application of skin tube, skin drum, microsurgery technology, axial flap, etc., which is a milestone achievement in the history of plastic surgery development, and it is a brand-new, safe, effective and widely applicable new technology and method of plastic surgery. Tissue expansion is usually performed in two phases. In the first stage of the procedure, an appropriate donor area is selected at the periphery of the defective area, and the expander is implanted through a small incision under the skin or muscle layer, and then the tissue is sutured in layers, and after the small incision is completely healed, sterile saline is injected from the syringe jug at regular intervals. Approximately once a week, the volume of each injection should be 10-20% of the volume of the dilatation capsule. For example, for a 400 ml dilatation capsule, the amount of saline injected each time should be 40-80 ml. The required dilatation time is usually 3-8 weeks. When the skin expansion reaches the expected requirements, the second stage of the operation can be carried out, that is, through the original incision to remove the tissue expander, excise the defective area of the scar or diseased tissue, the skin has been expanded to a certain extent to promote or rotate to the defective area, after plastic surgery and suture surgery to complete the whole process. Skin expanders are more commonly used on the head. Scarring baldness (due to burns, trauma, scalp avulsion, infection, surgery and other causes of scalp defects, hair follicles can not regenerate, the formation of scarring limited baldness), scalp defects with cranial exposure or defects, seborrheic baldness by drug treatment hair can not be regenerated, head tumors and nevus, can be pre-dilated in the vicinity of the lesion and then excise the diseased tissue, and cover the trauma with the expanded scalp. Scalp expansion despite the epidermis and deep tissue growth and expansion, the number of hair follicles did not increase, so in the expanded flap, in fact, the redistribution of the remaining hair, postoperative hair in the donor area has become sparse, but due to the distribution of uniformity, the effect is still more satisfactory. Scalp dilatation is suitable for patients with a limited breakout and is not suitable for patients with diffuse baldness or excessive baldness (usually no more than 1/2 of the scalp). Of course, this technique can also be applied to the treatment of scars or lesions in other parts of the body, especially after the excision of huge skin lesions and tumors, using the surrounding normal skin and soft tissue expansion for trauma repair with satisfactory results. In addition, the dilator technique can also be applied to total nose reconstruction and partial nasal defect repair, auricular reconstruction. In recent years, controlled tissue expanders have also been used for breast augmentation mammaplasty, with satisfactory results. It is believed that in a few years, this tissue expander will play a greater role in the field of cosmetic surgery.