With a narrow foreskin opening, the penis body is partially buried and cannot be revealed. The occult penis is a congenital developmental abnormality disease, which is a congenital malformation due to the penis skin not normally attached to the penile corpus cavernosum, so that the penis is hidden under the skin. There are generally two cases: one is caused by a thick layer of fat, this situation is still normal; the other case is the real occult penis, because the skin of the abdomen is not tightly attached to the penis extension, but directly connected to the coronal groove of the penis head, as if to the penis spongy body on a bat sleeve, so that you can not see the cylindrical penis, only see the exposed penis head. There are two types of occult penis: complete and partial. Complete occult penis means that the skin of the penis is too short and not attached to the penile corpus cavernosum at all, resulting in the penis body being completely shrunken under the skin, with an appearance like the absence of the penis, and only when urinating, the short penis is exposed. Because the penis is too short, the phenomenon of wetting clothes and pants when urinating is quite common; partial type of occult penis is the penis skin attached to the penile corpus cavernosum, the penis skin is too short and not very serious, so that the exposed part of the penis is like a cone-shaped circumcision mound. Clinically, it is necessary to distinguish occult penis and small penis by the following methods: from the head of the penis onwards, feel the spongy body of the penis along the skin, if the size of the spongy body felt is similar to that of the same age, it may be occult penis. If the spongy body is very short and thin, which does not match with the same age, it may be micropenis. Diagnosis is based on:short appearance of the penis; a normally developed penile body hidden under the skin; a normal penile body can be exposed by pushing the skin towards the root of the penis with the hand, and the penile body retracts rapidly after releasing. Treatment: A few children with occult penis can grow with age, reduce fat and mature with puberty, and the penis can return to normal shape without surgery. Surgery: The principle is to completely remove the abnormal development of the penile meatus tissue so that the penile body can fully extend forward. The subcutaneous tissue at the root of the penis and the white membrane of the corpus cavernosum are sutured to prevent retraction of the penile body. The scrotal angle of the penis is reconstructed to improve the appearance of the penis after surgery. Increase the skin coverage of the penile body using various modalities. The penis has a short appearance, with most of the penile body not being revealed and the foreskin not being retracted. The child is overly obese and has a fully encapsulated penile body, but the prepuce opening is not narrow and can be turned up, and the testes are small bilaterally, requiring aggressive weight control.