The sexual physiological development of children is closely related to age. The age at which puberty is initiated is influenced by many factors such as genetics, nutritional status, living conditions, climate, altitude, socioeconomic factors, and serious childhood illnesses. In recent years, due to economic development, changes in the ecological environment, and a surge in the amount of sexual information stimulation, there has been a trend toward early sexual maturation in children around the world. Children are exposed to a large number of risk factors in their daily living environment, including air pollution (including indoor air pollution, tobacco smoke), household water safety, personal hygiene and sanitation, vector-borne diseases, chemical hazards (such as lead poisoning, unsafe use of pesticides and aerosols) and accidental injuries. (e.g. lead poisoning, unsafe use of pesticides and sprays) and accidental injuries, which have a greater impact on children’s health, are the six most important risk factors that should be given priority attention. Toxic substances emitted from modern homes can easily enter children’s bodies through the skin and respiratory tract, and can also “ripen” children. If long-term exposure to various pollutants in the environment during childhood, may cause damage to the nervous and immune systems, the development of reproductive function, these damages will be evident in adulthood. Therefore, it is important to avoid children’s exposure to important chemicals that affect health, including metals (lead, mercury and arsenic, etc.), pesticides, persistent organic pollutants (PCBs, etc.), household products (solvents, pharmaceuticals, cleaning agents, etc.), etc. Geographical environment affects the development time of children Girls in China and Cuba, the Mediterranean area, due to the influence of genetic factors of ethnicity and the role of geographical environmental factors, the first menstruation is earlier, and the height of the terrain can also affect the launch time of puberty, the general terrain every 100 meters higher, the first menstruation of girls about 3 months later, so the lower terrain of China’s southeastern coastal areas of girls earlier age of sexual maturity exogenous sex hormones induce precocious sexual maturity. The research data of some scholars in China shows that, besides social and economic factors (such as the increase of information on sexual stimulation in society and the improvement of living standard), an important reason is that many parents are not cautious enough to make some exogenous sex hormone stimulation induce precocious sexual maturity in children. Most of the cosmetic products marketed in the market today, such as facial cleansers and snow creams, contain estrogen and progesterone, some of which are quite high. Light exposure reduces melatonin secretion leading to precocious sexual maturity Foreign researchers have also found that prolonged exposure of children to artificial light sources such as television may lead to precocious sexual maturity, including the early age of unmarried teenage pregnancy. Therefore, we do not advocate that children sleep with the lights on, because sleeping with the lights on will hinder the functioning of the pineal gland in the human body, possibly leading to precocious sexual maturity. So, what is the pineal gland actually? It is understood that one of the functions of the pineal gland is to secrete a large amount of melatonin at night when the body goes to sleep. This hormone is most secreted late at night from 11 pm to the early morning of the next day, and stops being secreted after dawn when there is a light source. However, the pineal gland has a characteristic that as soon as the eye sees a light source, melatonin will be suppressed or stopped. If children are exposed to too much light, it will reduce the secretion of pineal melatonin, causing sleep disturbances that may lead to early secretion of follicle-stimulating hormone, leading to precocious sexual maturity.