In this study, the key competency indicators for elementary school students are preliminarily constructed through document analysis. Through the Delphi technique, these indicators are further established with suggestions and corrections from scholars and experts. Moreover, the weight distribution of the key competency indicators is discussed through the analytic hierarchy process. The results show what the Delphi technique experts are most concerned about is the ”self-development” dimension of ability, while the second layer of index weigh most in the competency of ”understanding of oneself” level.Five conclusions are drawn from this study: (1) the key competency indicator system includes three major dimensions of 17 levels of indicators; (2) the ”self development” dimension is the most important in the first class; (3) ”understanding of oneself” is the most important level of self-development dimension; (4) in the interpersonal dimension, the most important level is that of ”respect and care for others”; (5) in the problem-solving dimension, ”the planning and practice of an organization” is the most important level.