According to the situation of self-study, the study is guided by cases. After the "study guidance plan" is issued before class, students can preview and study by themselves. In the classroom, teachers can accurately grasp the teaching objectives and learning situations according to the information feedback of students' independent inquiry, purposefully create and grasp the learning situations by means of introduction, demonstration experiments and modern educational technology, stimulate students' learning interest and motivation, and guide students to realize learning in the learning process. Students can focus on the key points and difficulties of learning based on the "learning guidance plan".