The survival time of sperm on underwear is short, about half an hour at room temperature, depending on the environment in which it is found. Sperm survival time varies in different environments. If in a dry, hot environment, the survival time is relatively short, usually less than 30 minutes, and may even die in a few minutes. If in a 37°C water bath, the survival time can be about 6-12 hours. If put into -195℃ liquid nitrogen freezing, it can quickly freeze the sperm, and after thawing the sperm can still be revived and survive longer than relatively. Sperm entering the female vagina through sexual intercourse can usually survive for about 5 days. In addition, men who want to increase their sperm can usually eat more foods rich in protein, fat and many vitamins, such as eggs, milk, nuts, as well as vegetables and fruits.