Children are afraid of being scolded by their parents, but they still can't restrain their desire for food and toys. If they do this for a long time, they will form the bad habit of always lying. Since parents know that their children can't consciously control the purchase of some junk food and toys, they should not just reprimand them, but often buy other delicious food for their children to distract their obsession with snacks. Of course, we should also tell our children some truth calmly or show them some movies or stories that are beneficial to them to warn them of the seriousness of lying. This cannot be changed in a day or two. Parents' role models are very important, and it is also necessary to strengthen guidance for children. Citing a principle of water control, it is impossible to solve the fundamental problem only by blocking water control. The important thing is to find a way to dredge and let the water flow to the final destination along the set trajectory.