Testicular cancer is one of the common tumors in urology. Testicular tumors are almost always malignant, of which germ cell tumors account for 90% to 95%, with seminomatous cell tumors being the most common. Non-germ cell tumors account for 5% to 10%. Testicular tumors are divided into two categories: primary and secondary, the majority of which are primary and secondary is extremely rare. The specific etiology is still not very clear, but it is believed that the cause is related to both genetic and acquired factors. Among them, it is most closely related to cryptorchidism, which has 10 to 14 times greater chance of tumor than normal, and is higher in the abdominal cavity than in the groin. Sperm must be generated at a temperature 2-3℃ below normal body temperature. Generally speaking, the most suitable temperature for male testes is between 34℃-35.5℃ to produce a large number of healthy sperm, and the testes are extremely sensitive to the influence of temperature. Once the temperature around the testes increases abnormally for some reasons, the spermatogenic function of the testes may become impaired or the spermatogenic epithelial cells may degenerate or even become cancerous, which is an important factor known to cause testicular cancer. In summary, the cause of testicular cancer is not very clear at present, but is initially considered to be related to genetic and acquired factors.