True anaplasia is a congenital abnormality of the penile surface, with a prevalence of about 0.67% in China. The skin of the penis is hypoplastic and there are often fibrous bands under the skin. It should be distinguished from obese pseudocryptorchidism, which is mostly seen in obese children, where the penis is deeply hidden under the skin due to the accumulation of fat in the abdomen and prepubic area, and there is no hypoplasia and subcutaneous fibrous cords. The diagnostic criteria for true occult penis in children should at least meet the following conditions: ① short appearance of penis; ② normal development of penile corpus cavernosum is hidden under the skin; ③ normal penile body is revealed by pushing back the skin at the root of penis, and the penile body retracts immediately after releasing; ④ except other concomitant penile malformations, such as hypospadias or epispadias, idiopathic micropenis, etc.; ⑤ except obese pseudocryptic penis. The age of surgery for true anaphylactic penis can be around 3 years old or younger, and it is decided by the doctor according to each child’s penile development. It can be done before they remember or before they start kindergarten, so that they are not known to outsiders and are not discriminated against. The surgery normalizes the appearance of the penis so that further development is not affected.