Recently, an overly obese child was admitted to our hospital. He was ten years old but weighed 48 kg, and the excessive fat on his abdomen and pubic bone made the whole penis buried under the skin, and only the small pointed foreskin protruded outside. After careful examination, we found that if the patient simply underwent anaphylaxis and lengthening, the result of penile exposure after surgery would be unsatisfactory. Therefore, we decided to perform fat aspiration on the pubic bone first and then perform anaphylaxis and lengthening, so that after the surrounding fat was removed, the penis would be completely exposed and the postoperative appearance would be more satisfactory. After being admitted to the hospital, the preoperative examination was completed and no obvious contraindications to surgery were found, and the suprapubic fat aspiration + anaphyseal phalloplasty lengthening surgery was performed on the second day. He came to the hospital for follow-up 5 days after the surgery and observed that the penis could be exposed 2cm in its natural state and the appearance was satisfactory. Many people may not be familiar with occult penis, so here is a brief introduction. The concealed penis is a congenital abnormality of penile development in children. The distal end of the urogenital sinus, which normally extends to the genital nodes during the embryonic period, is not fully developed, so that the penis is concealed under the skin and a small foreskin is exposed outside. The epidemiological survey found that the prevalence of occult penis is 0.68% among adolescent penile malformations, second only to prepuce and prepuce. In recent years, with the attention of clinicians and the increase of obese children, the incidence of occult penis is also increasing. This can affect the growth and development of the penis, and it can lead to low self-esteem and other psychological problems, which can also lead to future sexual life. It is possible to treat occult penis, not by drugs, but mainly through surgery to correct the deformity. The results of surgical treatment are still relatively satisfactory, achieving a columnar penis, a larger appearance, and eliminating the adverse effects on further growth and development. Therefore, those who are found to have short penis must go to an experienced urologist to avoid delaying treatment.