The so-called "math diary" means that students record their understanding and learning experience of a certain mathematics content in the form of diaries, evaluate the gains and losses of teachers' teaching and their own learning, put forward their own requirements for mathematics teaching, and ask teachers for various problems they encounter in mathematics learning. "Mathematics Curriculum Standard" points out: "Teachers should make full use of students' existing life experience and guide students to apply their learned mathematics knowledge to reality, thus reflecting the application value of mathematics in real life". As math teachers, how do we understand this challenging subject under the new curriculum, how to develop students' potential and ability, and how to promote the integration of disciplines? These are really worth thinking about. To solve this series of problems, it is a good way to carry out the research on students' math diary.