A cyst in the bend of the leg, equivalent to the popliteal fossa, is very unlikely to heal on its own. The cause of popliteal cysts is related to prolonged chronic strain, localized fasciitis of the knee joint, which gradually develops into an exudate and eventually a cystic lesion. The gradual increase of the cyst will also compress the popliteal vein and nerve of the lower limb, and the patient will also experience local pain and numbness of the lower limb, which will worsen after activity, and will also induce lower limb edema and even the formation of venous thrombosis, which should be actively treated. Mild cases can be selected for puncture aspiration under local anesthesia, pressure bandaging, or injection of sclerosing agent in the capsule, which can also promote the adhesion of the intestinal wall. Severe cases need to be further selected for surgical treatment to remove the lesion, but there is also the possibility of recurrence after surgery, and attention should also be paid to local pressure bandaging after surgery.