In principle, breast milk and formula should not be mixed together as much as possible. Mixed feeding consists of two methods, as follows: First, one feeding is exclusively breastfeeding, or exclusively formula feeding, and then changing to the other method when feeding the child next time, alternating between the two feeding methods. Of course, if the amount of milk secretion is relatively large, and there is sufficient breast milk secretion before the next feeding, you should try to breastfeed. Secondly, you can let your child suckle the milk from both breasts first. If the milk from both breasts can satisfy your child’s demand, you don’t need to feed him with milk powder. If the milk in both breasts is completely empty and still not full, you can then mix a small amount of formula for the child to eat. This method is likely to cause indigestion in babies and is generally not recommended.