Almost all human activities are inseparable from thinking, which is the information processing activity and function of the brain, and thinking ability may be the only ability for human beings to surpass other animals. Educational activities not only depend on people's thinking, but also greatly affect people's thinking. Education has two influences on thinking. On the one hand, it is "what to think", that is, the content of thinking, such as making people accept the spiritual civilization created by human beings. On the other hand, "how to think" refers to the forms, methods and rules of thinking, such as making people master and use image thinking and logical thinking. People are born with the thinking ability of feeling, memory, association, reasoning and imagination, but the standardized application of thinking ability, especially logical thinking ability, needs to be cultivated. The popularization of rational thinking contributes to the harmonious development of society. Formal logic is an important course to cultivate rational thinking, which is closer to daily life and work than mathematical logic. For example, the state recruits civil servants and legal workers, and the formal logic has special problems. Rational thinking is not only necessary for government and legal work, but also permeates all aspects of human activities. If we only take systematic formal logic teaching as a course in the higher education stage, it may affect many people who have lost the opportunity of higher education to think rationally in their daily life and work, which is a regret and loss in life. Education should enable all people to skillfully master and consciously and independently think rationally, and strive to avoid falling into the misunderstanding of thinking. Compulsory education is the golden age for the formation of teenagers' thinking mode and ability. Although the mathematics course at this stage is very important for cultivating students' thinking ability, it is still difficult for many students to transform their knowledge of mathematical logic into formal logic, which leads to a considerable number of people not cultivating the habit of using rational thinking in daily life, study and work. Therefore, it is necessary to carry out systematic and complete formal logic teaching in the compulsory education stage.