Shaping a harmonious and warm family environment is a key link in the development of teenagers' mental health. To protect the mental health of teenagers, families and schools need to coordinate and communicate in time. The outline for China's children's development (2021-2030) recently issued emphasizes that promoting the healthy growth of children can provide valuable resources and inexhaustible driving force for the country's sustainable development. In the reply of the Ministry of education to the proposal on further implementing the prevention and treatment measures for adolescent depression at the fourth meeting of the 13th National Committee of the Chinese people's Political Consultative Conference, it was clearly proposed to include depression screening in students' physical examination. Adolescent mental health is an important public health problem that can not be ignored, which is related to the growth of adolescents. To protect teenagers' mental health in an all-round way, we need to use the perspective of ecosystem theory to build a defense line through two-way interaction. The school should use the lifelong development theory and the concept of "three complete education", establish a unified curriculum system, and formulate a scientific curriculum outline, curriculum standards, Curriculum textbooks and evaluation system. At the same time, we should see that mental health education, especially the intervention of psychological crisis, is a particularly complex, scientific and practical educational activity. It is urgent to establish a strict access system and strengthen the construction of teachers. Schools should strengthen mental health education and establish "one policy for life" mental health archives for students. We should also regularly evaluate students' mental health status, realize the effective connection of file information in different sections, and solve the difficulties faced by different sections of mental health education. *** Parents should pay attention to their children's moral quality, physical quality, life skills, cultural cultivation, behavior habits and other aspects, so as to promote their children's all-round and healthy physical and mental growth. To protect the mental health of teenagers, families and schools need to coordinate and communicate in time. The family education promotion law clearly points out that the school family communication channels should be unblocked and the mutual cooperation between school education and family education should be promoted. Schools can fully understand the family environment in which students grow up through home visits, popularize mental health knowledge through online and offline platforms, and guide parents to establish correct educational concepts and master correct educational methods. We should closely cooperate with the implementation of the "double reduction" policy to effectively reduce the unnecessary schoolwork burden of children, so as to ensure sufficient sleep time and certain leisure time. At the same time, family and school should strengthen cooperation in the prevention and intervention of psychological crisis. Through in-depth counseling, schools should timely understand students' family situation, so as to establish a long-term and dynamic cooperation mechanism, coordinate and grasp students' psychological dynamics in time. Cultivating socialist builders and successors with all-round development of morality, intelligence, physique, beauty and labor is an inevitable requirement for us to adhere to the socialist school running direction. Therefore, we should fully implement the party's education policy, develop quality education, care about the mental health of teenagers, form a social joint force with multi-party participation, strive to build a high-quality and balanced basic public education service system, and cultivate more new people of the times who are responsible for national rejuvenation. (outlook new era)