Suggestion: The best time for phimosis operation is after the preschool age of 4-5 years. If the patient has repeated urinary tract infections or spots are formed between the foreskin and penis, the operation should be performed as soon as possible. The phimosis is that the foreskin mouth is narrow, and the foreskin cannot be turned outwards, so that the penis head cannot be exposed. The phimosis can be divided into congenital phimosis and acquired phimosis. Congenital phimosis refers to the fact that the foreskin of children cannot be everted at birth, which hinders the development of glans penis and even the whole penis. Its foreskin mouth is like a pinhole, and some even have difficulty urinating. Acquired phimosis is mostly secondary to dermatitis caused by excessive prepuce, or damage to prepuce and penis head, scar contracture at prepuce mouth, loss of elasticity and expansion of skin, so that the prepuce can not retreat downward. If children with complete phimosis are not treated, it will have an impact on their sexual life after adulthood. Due to the stimulation of inflammation and dirt in the foreskin, the probability of suffering from penile cancer will also be greatly improved.