At present, there is no unified definition of "vocational education" in theoretical circles. The interpretation of Ci Hai is: "Educate students or on-the-job personnel with the knowledge, skills and attitudes needed to engage in certain production and work." The definition of the World Bank is: "Vocational education is to prepare skilled workers in schools, and some courses are specialized vocational theory and practice; Technical education refers to the establishment of technicians, mostly after middle school. Most of these institutions are called polytechnics or industrial institutes. At the second vocational and technical education conference held in Seoul, UNESCO used the concept of technical and vocational education and training (TVET) for the first time, including "technical education" to cultivate technical applied talents and "vocational education" to cultivate skilled and operational talents. It can be seen that vocational education should include vocational training, job-transfer training, apprenticeship training, on-the-job training, job-transfer training and other aspects, which can be implemented by vocational training institutions in schools or society. It is a part of school education and social education and an important part of lifelong education system. Scholars have their own opinions on the vocational education system, which mainly focus on the following aspects: focusing on the diversion after junior high school, coordinating general education, vocational education and adult education; In addition to junior, middle and advanced levels, it should also be extended to undergraduate and graduate students, so that people who receive vocational education can obtain higher-level academic qualifications; Pre-service and post-service connection, communication with other education, coordinated development, etc. All belong to pre-service education and the system built from the inside of vocational education. According to the definition of the World Bank and UNESCO, vocational education in China (many engineering and medical universities) has been extended to doctoral level. For example, "MBA" is called "vocational degree" abroad, but it is not divorced from general education in China. It is only a narrow system to discuss "connection" and "docking" from the inside of education. What can really be called a modern vocational education system should include every restrictive factor in the social chain of vocational education development, such as vocational qualification system, employment access system, personnel distribution system, government management and investment system.