Nowadays, one of the most important areas in foreign policy is public diplomacy. With the advent of modern media especially social networks, new areas have been provided to pursue public diplomacy. with the development of the concept of soft power and enhancement its position in the area of national security, the concept of public policy, especially on social networks, has become more important, but there has been limited activities in our country on this area. Therefore we require a model to pursue our country's public diplomacy on social media; A model that is capable of analyzing, describing, and prescribing in this field. In this study, we formulated and introduced the model using the Grounded Theory method. Therefore, twenty professors, agents, experts and pundits were interviewed and Three superior documents were reviewed and the final model was extracted after coding. In our final model, the public diplomacy of mixed networks in social networks was introduced as central issue. Also, we introduced Causal condition , Intervening conditions, Background conditions, Strategies and the Consequences of their implementation as the sub-objectives of the research. Introducing the issue of public diplomacy of complex networks in social networks, and its dimensions are the innovations of this research.