There is a particularly hard line like under the skin of the penis, which is commonly caused by penile sclerosing lymphadenitis, penile cavernous sclerosis, penile dorsal superficial phlebitis and other causes. It is recommended that the patient go to the hospital in time to improve the relevant examination and clarify the cause of the disease. 1. Sclerosing lymphangitis of the penis: the typical manifestation is the appearance of painless striated elevated swelling in the coronal groove or the back of the penis, which is earthworm-shaped or irregular, and can slide under the skin. 2. Penile fibrosing cavernous inflammation: patients often show that there are single or multiple fibrous plaques in the penis, and the pain is obvious when the penis is erected. Oval or striated single or multiple hard nodules or plaques on the corpus cavernosum or tunica albuginea can be found. 3. Dorsal superficial phlebitis: the main symptom is the dorsum of the penis can be seen along the superficial veins along the superficial cord-like nodules. The acute stage is also accompanied by local redness, swelling, heat and pain. There is a particularly hard line like under the skin of the penis, it is recommended that the patient go to the hospital in a timely manner to improve the relevant examination, to clarify the cause of the disease.