Mathematical language is a subject language reflecting the characteristics of mathematics, which has the characteristics of scientific accuracy, strict logic and complete expression. Students' mastery of mathematical language expression ability will directly affect their subsequent learning and thinking ability development. We should also pay attention to cultivating students' language expression ability in math class. In actual teaching, I found that some students speak accurately, concisely and clearly. Some students are incoherent and can't express their views correctly. We all know that "only those who think clearly can make it clear, and those who make it clear must think clearly". Language is the material shell of thinking, and the results of people's thinking and cognitive activities are expressed through language. It can be said that the cultivation of mathematical language expression ability is the cultivation of mathematical thinking ability. How to cultivate students' mathematical language expression ability? First, teachers should have an inclusive attitude, so that students can speak and dare to speak. The methods used are bound to be diverse due to the different life backgrounds and thinking angles of students, and there are bound to be many immature and even naive methods. But for students, as long as they use their brains to come up with a good method, at least for students, it is to challenge themselves and start thinking. Therefore, teachers should be tolerant, encouraged, not eager to evaluate, and not suppressed. The only way is to be excellent. By comparing the characteristics of various algorithms, students can be guided to choose the method that suits them. As long as students' enthusiasm is not suppressed in this way, over time, students can show positive expression and communication if they dare to talk and think.