Children aged 7 ~ 14, during this period, parents should systematically educate their children about sexual knowledge. When talking about sex with pre-adolescent children, we can use natural phenomena, fairy tales and fables to insert the content of sex education in a metaphorical way. Parents can start with the flowering and fruiting of plants and then connect with human sexuality and reproduction. There is a saying that a beautiful girl planted watermelon seeds in the field in spring, and then she watered and fertilized the seeds every day, and the seeds slowly grew green leaves. In summer, the leaves bear small flowers, and the flowers wither and become small watermelons. The small watermelon grows bigger and bigger, and becomes a mature, sweet and delicious watermelon. You can pick it and eat it at this time. Mother also planted a seed in her stomach. Under her careful feeding, the seed grew up slowly and became a villain ten months later. Then her mother took it off and a lively baby appeared in this world. When watching programs such as Animal World, parents can also use animal reproductive activities as metaphors to talk with their children about butterfly mating, goldfish or chicken and cat reproduction. So as to help children understand sexual knowledge, avoid introducing human sexual behavior directly and in detail, and avoid bringing adverse effects to children of this age. At the same time of sex knowledge education, we should carry out sex moral education to help teenagers control their sexual impulses in the bud and prevent mistakes.