Zheng Guanying's anti-opium thought reflects his thinking on the opium problem as a reformist thinker in the Tongguang period, which has distinct characteristics of the times. The emergence of new forms of the opium problem in the 1860s and 1890s, Zheng Guanying's own experience, and his deep understanding of the situation of opium poisoning China, promoted the formation of his anti-opium thought. Zheng Guanying's anti-opium thought can be divided into two aspects: external prohibition and internal prohibition, and stresses the idea of "external prohibition is necessary before internal prohibition". External prohibition is centered on the "opium-field war", advocating the quick banning of opium poppy cultivation, increasing the tax rate of the "western medicine", and establishing opium specialized companies; systematic internal prohibition measures were put forward, urging the Qing government to take resolute action and motivate the whole society to solve the opium problem. His anti-opium thought had the irrational element of modern economic nationalism, but also contained certain rationality as a theoretical guide.