Accurate presupposition and accurate grasp of teaching materials, teaching syllabus or standards reflect the learning of basic materials. Teachers should deeply understand the basis of teaching materials and reorganize the teaching materials according to the actual teaching style. Presupposition not only violates the concept of teaching materials, but also leaves traditional presupposition in a blank state. Teachers pursue the perfection of the classroom and even design the classroom to say every sentence. The course is definitely used less by teachers. Resist listening to the real idea, try to pull out the existing phenomenon of preset answers, teachers prepare lessons, construct linear teaching plans, ignore the complicated process of classroom teaching, preset flexibility and leave blank. Second, rational classroom teaching is ever-changing, and presupposes that they can foresee classroom situations, and then excellent teachers can try their best to master classroom questions. Children's respective perspectives always belong to self-discovery, and different presuppositions deviate from the teachers' presuppositions when they cross the heights of the peaks. Teachers need to choose, integrate or even abandon the original presupposition according to the actual situation, so