Lu Xun’s novel Kong Yiji is short in length but grand in tension. Under the background of the era of high-spirited May Fourth Movement, his simple and unadorned narration of life restores the original social scene and advances Lu Xun’s rational thinking on Enlightenment. The juxtaposition of “abstraction” and “difference” in the novel and the coexistence of cultural conflicts between “Dao” and “Shi” highlight Lu Xun’s sober awareness of the status quo of Chinese society and ideological enlightenment. The calm narrative style of Kong Yiji is an external manifestation of Lu Xun’s enlightenment critical rationality, and his novel creation has shifted from fanaticism to rationality, demonstrating the development and new changes of enlightenment critical rationality.