Treatment based on syndrome differentiation is an essential feature of traditional Chinese medical diagnosis. The interventions based on changes of syndrome types in randomized controlled trials are complicated, leading to the difficulty of blind method enforcement. This article described a double-blind method. It could be used in randomized controlled trials under the condition of different syndrome types and different medications. It numbered drugs in two stages, and in two phases to achieve double-blind. This method not only guaranteed investigators and subjects to be in blinded conditions, but also achieved using different medications for patients of different syndromes. It also caused no drug waste. It was scientific and feasible.