For young girls, premature sexual behavior is more harmful to their physical and mental health and life development, and premature sexual behavior will lead to unexpected pregnancy. The harm of teenage pregnancy to teenage girls is mainly in three aspects: in terms of health, the development of teenage reproductive organs is not fully mature, and it is easy to cause complications such as anemia, dystocia, infection and massive bleeding after pregnancy, induced abortion of teenage girls is easy to cause complications such as infection and infertility, and the incidence of cervical cancer among early sex workers is also high; In terms of mental health, pregnancy and abortion will make girls feel inferior, suffer social humiliation, lose their ideals and beliefs about future life, and psychological guilt will cause nervousness, insomnia and other neurosis. If young girls give birth, the responsibility of raising and educating their children often falls on them, which makes them lose the opportunity of learning and further development and affects their quality of life.