Tendon cysts are most often seen in the back of the foot. It is caused by chronic strain and other reasons. They are usually round with clear borders and firmness, and some may be associated with pressure pain. Treatment is mainly conservative, including compression or pressure breaking. If conservative treatment is ineffective or recurrent, surgery can also be performed. Surgery is performed under local infiltration anesthesia, and the skin should be carefully separated after incision to avoid rupture of the cyst as much as possible; once the cyst is ruptured, the entire cyst wall should be completely removed after aspiration of mucus. The cyst should be separated to the base to avoid damaging blood vessels and nerves, and when the cyst is connected to the joint cavity or tendon sheath, the tip should be removed completely. The incision left open should not be sutured or ligated to avoid recurrence after surgery, and medication should be changed on time after surgery to observe changes in the incision to avoid infection.