The educational purpose determines the educational content, and the educational content embodies the guiding function of the educational purpose. The purpose of education is the starting point and destination of educational activities, which stipulates the direction and goal of education and is the guiding ideology of educational activities. The choice of educational content, the application of teaching methods and the standard of teaching evaluation must be carried out around the educational purpose in order to meet the requirements of educational purpose. The guiding function of educational purpose is an important guiding function of educational activities, which determines the direction and goal of education and is the soul of educational activities.