Lu Xun's Kong Yiji was a short story that criticized the darkness of society and the distortion of human nature by describing a poor, humble and cunning little character, Kong Yiji. The main idea could be summarized as the following: Criticizing the darkness and exploitation of feudal society: The novel uses Kong Yiji's situation as an example to show the darkness and exploitation of feudal society, especially the corruption and injustice of the imperial examination system, which led to many people being oppressed and exploited and living in poverty and inferiority. 2. The novel highlights the distortion and injustice of human nature through the story of Kong Yiji. Although Kong Yiji was a poor and humble nobody, he was greedy, cunning, selfish, and was discriminated and oppressed by society. This kind of distortion and injustice of human nature reflected the injustice and darkness of society at that time. 3. Calling for social progress and human concern: Through the story of Kong Yiji, the novel calls for people to pay attention to the injustice of society and the distortion of human nature, and to seek social progress and human concern. Through Kong Yiji's fate, the author expressed his concern for social justice and humanity, and also called on people to bravely face reality and pursue truth and freedom. Kong Yiji is a profound social novel. It reflects the darkness of feudal society and the distortion of human nature by describing the fate of a small character. It calls for social progress and human concern.