Sebaceous cysts are commonly known as “powdery tumors”. It is a retention cyst formed mainly by the obstruction of the sebaceous gland drainage ducts and the expansion of the sebaceous gland cystic epithelium by the gradually increasing contents. The cyst is filled with white curd-like sebaceous secretions. Clinical manifestations are diverse: 1. Commonly found on the face where sebaceous glands are abundant, small ones are like beans, and large ones can be as small as citrus. The cysts are round, located in the skin, and protrude towards the skin surface, the cyst wall is closely adhered to the skin, and there may be a small pigmented spot in the center. The grayish-white curd-like, foul-smelling contents may occasionally flow. 2, sebaceous cysts occur slowly, round, with obvious boundaries with surrounding tissues, soft texture, no pressure pain, and movable. Generally there are no conscious symptoms. 3, sebaceous cysts secondary to infection can be manifested as: local skin redness, swelling, softening, skin temperature increase, pain, pus. The treatment is general outpatient surgical excision under local anesthesia. A shuttle-shaped incision is made in the direction of the skin line, and the skin including the adhesions with the cyst wall should be removed, and the cyst wall is removed completely by sharp separation after cutting the skin. The cyst can also be carefully removed by cutting the skin in a straight line in special areas. Generally, it should be cut to the fat layer. The cyst wall is usually very thin and rupture should be avoided. If the cyst is complicated by infection, the cyst should be excised by incision to drain the pus and bean residue-like contents and surgically removed 3 months after the infection is controlled. Oral antibacterial drugs can be administered if necessary.