Usually, after 5-6 months of age, infants are encouraged to start adding complementary foods, and the principle is to add from less to more, from thin to thick, from less to more, just to taste at first, and then gradually add the amount after adapting. Most formula-fed infants can add complementary foods at about 5 months, starting with iron-containing rice flour, and then gradually adding other complementary foods such as puree, vegetable puree, and meat puree after the gastrointestinal adaptation. Babies who are exclusively breastfed can delay the addition of complementary foods until after 6 months of age. In addition, the addition of complementary foods should also be decided according to the growth and development of infants, such as the head and neck muscles are well developed, their swallowing function is gradually coordinated and mature, and no longer spit out the food on the tongue, then it is a good time to add complementary foods. The addition of complementary foods for infants is a gradual process from fine to coarse, and it is necessary to ensure the diversity of complementary foods, such as adding mainly rice paste at 5-6 months of age, adding pureed fine particles at 7-9 months of age, and adding coarse particles and small pieces of food at 10-12 months of age.