Lu Xun's " Blessing " was a classic novel of social criticism. Through the " I " observation of various characters at the birthday party and the description of their psychological activities, it revealed the darkness of society and the distortion of human nature at that time. This description mainly had the following functions: Revealing social reality: Through the observation of the characters at the birthday party, the novel reveals the darkness and injustice of the society at that time, including the sufferings of the poor and the hypocrisy of the rich. This kind of description helps readers better understand the social reality at that time and better reflect and criticize. 2. Enhancing the appeal of the novel: The changes in the psychological activities of the "I" in the novel make the changes in the emotions and attitudes of the "I" towards the characters more real and natural, thus enhancing the appeal of the novel. Through the emotional changes of "I", readers could understand the characters in the novel more deeply and feel the emotional atmosphere of the novel. 3. Prominent the theme of the novel: The changes in the psychological activities of "I" in the novel highlight the theme of the novel through the description and thinking of various characters 'emotions--the essence of human nature and social injustice. This kind of description helps readers better understand the theme of the novel and think more deeply about human nature and social issues. Lu Xun's " Blessing " described the changes in the psychological activities of " I ". Through the observation and reflection of various characters at the birthday party, it revealed the darkness of the society and the distortion of human nature at that time, which enhanced the appeal of the novel and highlighted the theme of the novel. It was of great significance to the reflection and reflection of the society and human nature at that time.