Lu Xun's Madman's Diary was a realistic novel narrated in the first person. It revealed the various ills of Chinese society and the distortion of human nature through the description of the protagonist Fang Hongjian's encounter in the mental hospital. In the novel, the madman referred to Fang Hongjian himself. He was soberly aware that he was in the world of mental patients. The people in this world seemed to have lost their rationality and judgment. Their crazy behavior and words shocked and terrified him. Madman hoped to find a truly free and rational way of life by escaping this crazy world. Through the image of the madman, the novel reflected the various problems of Chinese society at that time, such as the decadence of feudal ideas and autocratic rule, cultural repression and the distortion of human nature. At the same time, the novel also revealed the truth and complexity of human nature through the description of the madman, showing the process of human beings seeking balance between madness and rationality.