In general, it is normal for 12-year-old children to start growing hair. Twelve-year-old children are in puberty, the body organs grow faster, the body secretes more sex hormones, height, weight and so on will change accordingly. Boys will appear throat knot, penis, underarm hair growth symptoms, at this time the girl’s breast development faster, pubic hair, armpit hair will also grow. Due to personal diet, genetics and other factors, the growth and development of different individuals will also be different, some children develop earlier, the phenomenon of hair growth is also earlier, parents do not have to be too anxious. Parents should give their children a moderate amount of meat, dairy products, beans and other foods rich in protein, trace elements and other nutrients, to supplement the child’s growth and development of the required nutrients, and actively guide the child to exercise, enhance their own immunity. It is recommended that parents pay attention to make their children understand more about the knowledge of physical changes during puberty, and correctly guide their children to help them grow up happily and healthily.