Elective courses and compulsory courses have the same effect on students' development. However, due to the objectives, tasks, functions, teaching approaches and methods of elective courses, and even the characteristics of assessment, the teaching methods of compulsory courses cannot be simply transplanted into the teaching of elective courses, and the particularity of elective courses should be deeply studied. So, what are the characteristics of elective teaching? Here is a comparison with the required courses to illustrate. From the perspective of teaching objectives, compulsory courses focus on the formation of knowledge, skills and quality, laying the foundation for students' lifelong development, while elective courses focus on broadening their horizons, deepening their knowledge and skills, and developing their specialties and personalities. From the teaching function, compulsory courses impart basic scientific and cultural knowledge, skills and technology, guarantee basic academic ability, cultivate basic quality, and lay the foundation for personalized development and lifelong learning. Elective courses pay attention to the expansion and deepening of subject knowledge, meet students' interests and hobbies, and develop students' personalities and specialties. From the teaching content, compulsory courses emphasize the fundamentality, fundamentality, systematicness and integrity of knowledge and skills, and the content is relatively stable, while elective courses pay attention to deeper, broader and newer knowledge and skills and major issues in contemporary social life, which are flexible and must be adjusted in time with the changes of the times and the requirements of students. In terms of teaching methods, compulsory courses should be implemented linearly step by step, focusing on classroom teaching, discussion and exploration and strengthening basic skills training, while elective courses can be implemented nonlinearly, with expert lectures, students' self-study, discussion and practice as the basic forms. Of course, this difference is only relative. There are many similarities between the teaching of elective modules and the teaching of compulsory modules in subject courses. But even so, there are differences between elective courses and compulsory courses in terms of setting themes and task functions, which cannot be confused. Therefore, we should pay attention to the characteristics of elective courses, implement teaching according to the characteristics and laws of elective courses, and strive to improve teaching quality.