Cognitive structure refers to people's internal coding system about the real world, which is a series of interrelated non-specific categories. It is a frame of reference for people to perceive, process external information and conduct reasoning activities. Cognitive structure is simply the knowledge structure in students' minds. Generalized cognitive structure is the whole content and organization of students' existing ideas; In a narrow sense, it is the whole content and organization of students' thoughts in the field of specialized knowledge of a certain subject.

The individual's cognitive structure is to expand and improve the accumulated knowledge psychologically through assimilation in the learning process. Once a learner's cognitive structure is established, it becomes an extremely important energy or factor for him to learn new knowledge. K Lei Wen, a German Gestalt school topological psychologist, pointed out in 1930s that learning is a change of cognitive structure, which is manifested in three ways: differentiation, generalization and reorganization.