The invention belongs to the field of complementary food nutrition supplement and provides an infant complementary food nutritional bag and a preparation method thereof. The infant complementary food nutritional bag is prepared from the following components in parts by mass: 90-100 parts of instant tofu powder (with protein content being 18 percent), 6.1-7.1 parts of a compound nutrition enhancer, 15-21 parts of soy protein isolate (with sodium being smaller than or equal to 1000mg / 100g), 1.5-2.5 parts of freeze-dried apple powder, 1.5-2.5 parts of freeze-dried banana powder, 1.5-2.5 parts of carrot powder and 5.9-6.9 parts of whole milk powder. The infant complementary food nutritional bag is specially designed aiming to nutritional requirements of infants of 6-12 months, is rich in micronutrients including protein, iron, zinc, calcium, vitamin A, vitamin B1, vitamin B2, vitamin B12, vitamin D3, folic acid needed by growth and development in key window periods of the infants, is reasonable in proportion, definite in efficacy, clear in mechanism, remarkable in synergetic effect and liable to produce, accords with a national production standard published by Ministry of Health and is safe and reliable.