Tendon sheath cysts occur in the foot and ankle and are a relatively common site. When this disease occurs, the first thing the patient needs to do is limit excessive activity in the foot and ankle and reduce the amount of activity. This disease can’t be lowered by taking medications or injections. There are several ways to treat it: first, ask someone to apply impact external force to squeeze the cyst and make it break, as if there is a grape-like cyst inside, after the skin is broken, the fluid inside flows out and the cyst disappears. However, its internal cyst skin still exists, and there is a possibility of recurrence. Secondly, through aseptic technique, the contents of the cyst are extracted by using an empty needle and injected with prednisolone acetate, expecting adhesions to occur, thus achieving the purpose of healing. Thirdly, the cyst is completely removed under the condition of “no pain and no blood”.