There is no exact standard for when a newborn can go outside, and it needs to be analyzed on a case-by-case basis. If the newborn is in good health, and the outside temperature is suitable, the weather is better, the light is more suitable, then the newborn can go out at any time. The traditional concept that babies can go out only after the full moon is not scientific. Because the newborn can go out to receive sun bathing, promote the production of vitamin D, promote the absorption of calcium, but also contact with fresh air, conducive to infant health and growth and development, brain and intellectual development also has a good role in promoting. Therefore, when the outside air is better, less wind and better sunlight, newborns can go out for sunbathing and ventilation 1-2 days after birth. However, some premature infants are weak, too early to go out easy to get cold, need to be considered after the full moon to go out. In addition, newborns need to bring milk powder, diapers and a change of clothes before going out, and watch the weather forecast before going out to be fully prepared.