The article is devoted to the development of adult education, its andragogical principles and the impact on the quality of lifelong pedagogical education. The authors examined the mechanisms for improving the quality of lifelong pedagogical education by updating the content, developing and implementing innovative teaching technologies following new European guidelines and concepts in education, taking into account national educational traditions. In the article, the authors considered the basic concepts of andragogy, investigated the specifics of andragogical processes, the world experience in adult education. The authors noted that adult education today is based on continuous learning, self-education, and self-development. People will have to retrain 2-3 times in life; they will retrain at least once in adulthood. The research methodology is based on personality-activity and systematic approaches. As a result of theoretical and methodological research, the authors proposed a mechanism based on information technology (distance learning), the principles of androgynous learning and the specific features of adult learning (which the authors divided into three groups). This mechanism can increase the effectiveness of andragogical education in developing an educational trajectory. Further research is the search for ways of state financing of andragogical education and the development of indicators of its effectiveness.