An experiment used by modern cognitive psychology to study the psychological characteristics of people's problem-solving process. The initial state of the Tower of Hanoi problem has three pillars, A, B, and C. On pillar A, there are several disks with a hole in the middle, overlapping from large to small and from bottom to top, like a "tower". The target state is to move the "tower" to pillar C, with pillar B as a transition. The rule is that only the top disk can be moved at a time, and the large disk cannot be pressed on the small disk. It is required to explore the path from the initial state to the target state, and finally solve the problem and reach the target state. While thinking, the subject reports the content of thinking loudly. The main experimenter analyzes the thinking process based on the subject's oral report.