The sperm selected for single sperm injection are those with good motility, and the quality of embryos is relatively good if the sperm and egg are successfully united. The sperm used for single sperm injection are selected by screening for high quality sperm, except in cases of severe oligospermia or azoospermia, where it is recommended to increase the number of sperm in order to increase the chance of conception. The quality of embryos is affected by the sperm and egg, but also by the intrauterine environment, the individual’s emotions, the hormone level in the body and other factors. After sperm injection, it is recommended to maintain a good state of mind, get enough sleep, avoid overexertion, pay attention to nutrient intake and avoid sexual intercourse to provide superior conditions for sperm and egg union and improve embryo treatment.