The most basic feature of cryptorchidism is the poor attachment of the penile body to the skin and the small outer plate of the foreskin and the large inner plate. The purpose of surgery is to expand the foreskin opening and reveal the penis. The surgical method and efficacy are not consistent, but the ventral penile approach is a simple and effective surgical method, and after several years of practice, the efficacy of the author is definite. The results are reported below. Data and methods I. General data 150 cases of children with occult penis treated in our hospital from January 2008 to August 2011 were collected. The ages ranged from 3 to 16 years old, with a median age of 5.7 years. All patients were seen for short penis with bird’s beak shape or poor exposure, and had no history of urinary difficulties or recurrent urinary tract infections. On physical examination, the appearance of the penis in the natural state was significantly smaller than that of children of the same age, but the skin at the root of the penis could be exposed and a normal-sized penile body could be palpated by pushing back on it, and the penile body retracted after letting go of the penis, while the narrow prepuce opening could not reveal the penile head. There is no abnormality in the development of scrotum and testicles. Second, the surgical method Sacral block or intravenous compound anesthesia, the child supine position, routine sterilization. The prepuce is dilated, the head of the penis is tractioned with sutures, an inverted “V” incision is made at the ventral junction of the penis and scrotum, the penile fascia is incised longitudinally to the penile leukodermis, the gap along the leukodermis is sharply freed on both sides, the abnormal attachment of the penile root is completely loosened, and the leukodermis of the penis root and the penis are fixed with 0 silk sutures at 2 and 10 o’clock on the dorsal side of the penis. The dermis of the root was fixed with sutures at 2 and 10 o’clock on the dorsal side of the penis, and the sutures were locally depressed and not exposed, so that the penis was fully extended and exposed, and the skin incision was closed with interrupted 5-0 absorbable sutures. Then the foreskin is lifted, and the inner and outer foreskin plates are cut horizontally or wavily to release the foreskin stenosis ring, as the outer foreskin plate is small, the inner foreskin plate is left appropriately, and then the inner and outer foreskin plates are sutured together. The F8 to F10 silicone balloon urinary catheter was left in place, and a dressing was applied externally after the operation. Results In all cases, the penis was well exposed after the operation, and there was no obvious penile bending, twisting or skewing. The average increase in the length of the penis at rest was 2.5±0.5 cm; 4 cases of severe foreskin edema, 3 cases of epidermal erosion and 1 case of wound infection occurred after surgery, which were cured by changing medication. The majority of parents and children were satisfied with the appearance of the penis during the postoperative follow-up period of 3 to l2 months. A more reasonable explanation is that the distal end of the urogenital sinus, which normally extends to the genital nodes during the embryonic period, is underdeveloped, and the fleshy membrane of the penile skin becomes inelastic fibrous bands directly attached to the front of the penile body, which restricts the penis from extending forward, resulting in the inability to effectively stimulate the normal development of the penile skin during the development of the penis, thus making the penile body The penile body cannot enter the penile skin and prepuce cavity, and the penis is fixed under the skin of the pubic symphysis, leading to the occurrence of occult penis. The anatomical characteristics are that the penile skin is not attached to the penile body, the penile skin is short and the prepuce cavity is narrow, and the penile body cannot enter the penile skin and prepuce cavity. The diagnosis and classification methods of occult penis are not uniform at present. The comprehensive literature materials its diagnostic criteria should meet the following points: ① the penis is occluded in the subcutaneous tissue in front of the pubic bone; ② the appearance of the penis is short and cone-shaped, or only the residual prepuce-like penis is absent; ③ the development of penile corpus cavernosum and penis head is normal; ④ exclude penile malformations such as micropenis, webbed penis, hypospadias. Although the penis develops rapidly until puberty, many parents and children in preschool are concerned about penile morphology. Even if there is no obvious difficulty in urination, prepuce and urinary tract infection, the short appearance of the penis as the age increases will have a psychological impact on the child and parents, therefore, most scholars advocate early surgery, and surgery in preschool is appropriate. But at the same time, we should fully communicate with parents about the condition and the effect of surgery, and inform them that the purpose of surgery is to make the penis appear well, not to extend the length of the penis. In view of the clinical characteristics of occult penis, there are many surgical methods, such as Shiraki operation, Johnston operation, modified Devine operation, prepubic approach to penile meatus fixation, perineal prepubic local fat aspiration, fat excision and so on. However, most of the above procedures are complicated and not easy to master. Through the treatment of this group of cases, the author experienced that the ventral penile approach has the following advantages: (1) The incision is concealed, and it is easy to release and fix the penile meatus. (2) The operation steps are simple and easy to master. The operation time is about 40 min. (3) Avoiding foreskin decortication or flap transfer, which reduces the chance of postoperative flap necrosis or wound infection. (4) The appearance of the penis is good after surgery, which is easily accepted by the children and parents.