The child may cry at night due to two conditions: First, the child ate too much food before bedtime and did not digest it, abdominal flatulence causes pain in the child’s abdomen, resulting in crying performance, then you can wake the child, massage the child’s abdomen to help exhaustion, defecation, and parents should pay attention to not give the child too much food within two hours before bedtime. Parents can check the child’s trace elements to determine if the calcium deficiency is the cause, if the calcium deficiency can let the child get more sunlight or vitamin D supplementation, and at the same time, calcium supplementation treatment can be carried out.