Penile sebaceous gland ectasia refers to the sebaceous glands occurring on the penis. The etiology is still unclear and may be related to heredity, endocrine disorders, local irritation, skin trauma and other reasons. 1. Heredity: mainly related to congenital sebaceous gland ectasia. 2. Endocrine disorders: this disease often develops at puberty, until adulthood is more stable, so it may be related to endocrine disorders, which is mainly due to excessive secretion of androgens. 3. Local stimulation: including long-term contact with irritating substances, such as tobacco, croton oil, etc., followed by the long-term use of complex chemical composition of skin care products, long-term exposure to strong ultraviolet radiation and so on. 4. Skin trauma: studies have shown that breakage of the skin mucosa after trauma may also be one of the causes of this disease. To summarize, patients with sebaceous gland ectasia need to go to the hospital in time and cooperate with doctors to actively treat the disease so as not to delay the condition.