For decades, people have viewed narcotics as a devil impeding the modernisation of China, but they have recently been faced with the challenge of declaring that narcotics are harmless in some instances. A deeper understanding of this issue requires historical approaches which show that the demonisation of narcotics has mainly been a political pursuit. In re-examining the drug problem and its correlation to political and socio-economic issues, data statistics based on substantial archives in modern China play a crucial role. Discovered in 2007 in Longquan, a city in southeast China, Judicial Records of Longquan remains the largest judicial record in modern China by far. Data analysis reveals government efforts regarding drug control were not in line with the peak periods of drug-related cases in Longquan. Drawing on previously unexamined documents, it can be shown that anti-drug mobilisation and hygienic conditions have been overstated to legitimise the authority of governments in modern China. However, the knowledge of local residents regarding medicine and health was indirectly promoted in this agenda. Compared with the negative image of drugs constructed under the biopower of government, the role of narcotics was a positive vehicle for accelerating health mobilization during the Republic of China.