There is no such thing as proper mixed feeding, which is a way of adding formula when breast milk is insufficient or when it is not possible to breastfeed on time. Mixed feeding is mainly supplemental feeding method and substitute feeding method. 1. Complementary feeding: In this method, the number of feedings remains the same, and breastfeeding is done first, and then formula milk is used to replenish the insufficient portion after the milk is sucked out of the breasts. The amount of supplementation required is not clearly defined, but is usually determined by the amount of breastmilk and the baby’s milk supply. 2. Substitution method: This method is to replace one breastfeeding with formula milk, suitable for infants who are ready to be weaned, the feeding process should be gradual, increasing formula milk gradually replacing breast milk until it completely replaces breast milk. In the process of mixed feeding, we should pay attention to observe the baby’s condition, whether there is bad mood, abnormal bowel movement and so on, if the baby appears to be uncomfortable, it is recommended to consult a doctor in time.