Teratozoospermia is diagnosed when the percentage of normal morphological sperm is less than 4%. A sperm malformation rate that can reach 99% indicates a high morphological malformation rate of sperm and a significantly reduced chance of normal conception. There are many clinical causes of malformed sperm, both congenital and acquired factors. The first consideration is bad habits, such as smoking and drinking, nicotine in cigarettes and alcohol in liquor can cause sperm malformations. Second, environmental factors, work and life in contact with the environment with radiation and pollution or excessive exposure to chemical materials. Third, disease factors, such as the most common in clinical epididymitis, severe chronic prostatitis and severe varicose veins, can lead to testicular damage sperm deformities. Fourth, the temperature factor, the testicles are in a high temperature environment for a long time, such as soaking in a warm bath, sedentary, etc. Fifth, some patients are congenital chromosomal variants. Sixth, clinically special diseases and taking special drugs can cause sperm malformation, such as anti-cancer drugs. When the sperm malformation rate can reach 99%, the cause must be determined according to the actual situation of the patient, and there is a specific treatment for the cause.