Cryptorchidism is the most common abnormality of urinary tract development in children. If not detected in time, delayed treatment will affect fertility and cause serious complications, which will have adverse effects on the child’s life, so it should be taken seriously by parents. So, what is cryptorchidism? How is it formed? Cryptorchidism refers to a malformation in which the testicles do not descend into the scrotum bilaterally or unilaterally after the baby is born for 2 months. The cause of cryptorchidism is related to the following factors: 1. The testes cannot descend into the scrotum from their original position due to the degeneration or contraction disorder of the testes during the embryonic period; 2. The congenital testicular hypoplasia makes the testes insensitive to gonadotropins and lose the power of descent; 4. The lack of sufficient maternal gonadotropins during fetal growth affects the power of testicular descent; 5. Local factors such as mechanical obstruction or peritoneal adhesions prevent the normal descent of the testes. Cryptorchidism can occur unilaterally or bilaterally, with unilateral prevalence and right side slightly higher than left side. Cryptorchidism accounts for 10% of premature babies and 5% of full-term babies. Most of them can descend to the scrotum within 1 year of age; if they still do not descend on their own at 1 year of age, early testicular descent fixation should be performed, otherwise permanent anatomical changes will occur. Cryptorchidism has five main hazards: 1. Psychological disorders: no testicles in the scrotum, changes in the shape of external genitalia will make children have low self-esteem, reluctant to go to public bathrooms, and psychological abnormalities; 2. 3. Very susceptible to malignant change: Due to the change of growth environment and developmental disorders, the cryptorchid testis cells become malignant and form malignant tumors, the possibility of which is 35 times higher than that of normal testis; 4. Because the temperature inside the scrotum should be 1.5-2℃ lower than 37℃ body regimen, this “low temperature” condition is necessary for the testicles to produce sperm. Cryptorchidism does not have this “low temperature” condition, and the sperm production function is affected, thus causing male infertility. If the testicle does not descend after the age of 1 year, surgery should be performed to fix the descending testicle as soon as possible. At present, laparoscopic testicular fixation is mostly used for surgery, which is effective and the incision is concealed and beautiful.