The reason why the Chinese medicine practitioners in Lu Xun's novels were all surnamed He was because these Chinese medicine practitioners all came from the theoretical system of Chinese medicine at that time. One of the core concepts of Chinese medicine theory was "Yin Yang and Five Elements". Therefore, the names of these Chinese medicine practitioners often contained the surname "He" to indicate the theoretical system of Chinese medicine they belonged to. In traditional Chinese culture, the concept of Yin and Yang and the Five Elements was a very important concept that was widely used in philosophy, literature, science, and other fields. In Lu Xun's novel " A Madman's Diary ", the author used some philosophical ideas of Yin and Yang to explore the nature of human beings and the fate of society. Therefore, the surname "He" was included in the names of Chinese medicine in Lu Xun's novels to reflect the theoretical system of Chinese medicine mastered by these Chinese medicine practitioners.