Abstract: In the process of developing clinical practice guidelines, consensus method is essential to determine clinical problems and recommendations, among which Delphi method and modified Delphi method are the most common. Therefore, scientific and standardized application of Delphi method to reach a consensus (such as expert selection, process design) has become an important topic in urgent need of study. In the process of using Delphi method, it is necessary to refer to mature methodological suggestions to make theconsensus process structured and transparent. This article focuses on the key elements of Delphi method in the development of clinical practice guidelines, and elaborates its basic methods and processes, including the number, composition, standards and selection methods of the "expert group", as well as the key points of patients' participation. In terms of technical points, anonymity, consensus threshold and time control are described. Furthermore, the limitations of Delphi method and the highlights of the report are presented, in order to promote the standardized application of Delphi method in the development of the guidelines.