If children have a bad taste in their mouths, it is mainly due to the following conditions: First, if the taste of children’s mouths is mainly sour and rotten, mainly due to indigestion in children. Because children eat too much food, it will lead to food can not be effectively digested, so there will be indigestion, children not only have a sour taste in the mouth, often accompanied by abdominal pain and undigested milk flaps in the stool, food, etc., for this situation can be given to children timely application of anti-feeding and stagnation drugs. Secondly, ketoacidosis is caused by children suffering from ketoacidosis, if children usually suffer from type 1 diabetes and the application of insulin is not very standard, it will cause ketoacidosis. Ketoacidosis in children will cause coma and apple taste in the mouth, for this situation, children should be given timely treatment to reduce sugar.