Compulsory education is limited to nine years, which is also called nine-year compulsory education, including six years in primary school and three years in junior high school. Compulsory education is a national education that school-age children and adolescents must accept according to law and is guaranteed by the state, society and family. Its essence is a system of compulsory education for school-age children and adolescents for a certain period of time according to law. Compulsory education has the basic characteristics of compulsory, free, universal and secular.