First, prepare the emblem category (1) and choose the topic carefully. In the last lesson, in order to complete the teaching task in a limited time, we must carefully choose the topic. If the topic is small and specific, such as indirect proof and reduction to absurdity, the effect will be good. If the topic is big, such as choosing the relationship between straight line and conic curve, etc., the content is more, time is definitely not allowed, and the teaching effect is not ideal. (2) Prepare teaching materials. 1, prepare the starting point. The starting point of teaching should not be too high, it should conform to students' cognitive laws, and the starting point should be appropriate, which is conducive to promoting knowledge transfer; 2. Be prepared for the key points. When preparing lessons, we should highlight the key points of this class, closely follow the key points, supplemented by knowledge training, guide and inspire the understanding of key contents, so that the whole class has a soul; 3. Be prepared for difficulties. When preparing lessons, we should determine the teaching difficulties according to the breadth and depth of the teaching materials and the students' foundation. We must pay attention to analysis, study hard, grasp the key points and break through the difficulties. 4. Prepare the intersection. Mathematics knowledge itself is very systematic, and chapters, examples and exercises are closely related. Only by truly grasping the intersection of old and new knowledge can we integrate knowledge, communicate the vertical and horizontal links between knowledge and form a knowledge network. 5. Be prepared for doubt. When preparing lessons, we should combine students' basic and practical ability to find out doubts and help students solve difficult problems; 6. According to students' cognitive rules, carefully design teaching links, including design questions and exercises. (3) preparation method.