Lu Xun's Medicine was based on the national hygiene problem in modern Chinese history. Through describing a fictional story, it revealed the corruption of medicine and the predicament of people's health under the feudal system, showing concern and criticism for the feudal system and human nature. The clues of the novel mainly included the following aspects: 1. Drug administration corruption: The protagonist Xia Yu in the novel took advantage of her position as a drug administration official to purchase drugs wantonly and increase the profits of drugs through various means, resulting in the decline of the quality of drugs on the market and the threat to the health of patients. 2. Medical corruption: In the novel, medical scientists develop new drugs by hook or by crook in pursuit of personal gain, but they do not strictly supervise and examine the drugs. As a result, many drugs have toxicity and side effects, which pose a huge threat to people's lives and health. 3. Humanity care: Through the description of the protagonist Xia Yu and other medical workers in the novel, it shows their kindness, courage and sense of responsibility when facing patients and health. At the same time, it also reveals the difficulties and contradictions they face when pursuing personal interests. 4. Feudal system: Through describing the corruption and backwardness of the feudal system in the Qing Dynasty, the novel reveals the neglect and indifference of the feudal society to the health and lives of the people. At the same time, it also expressed criticism and reflection on the feudal system.