Online prosocial participation itself has great social significance, but compared with the research enthusiasm of network risk behavior in public emergencies, the academic community has not paid enough attention to it. To study this field, we should first clarify how to recognize, understand and measure it conceptually. Therefore, this paper designs a two-stage research scheme. Firstly, through the method of network text collection and content analysis, this paper analyzes the behavior categories of prosocial participation from the perspective of behavior performance, so as to analyze the specific behavior performance and initially form the conceptual dimension; Secondly, the general path of scale development is introduced to further explore and verify the conceptual dimension through empirical research, so as to develop effective measurement tools on this basis. It is found that network prosocial participation is an important content of users’ online participation; Online prosocial participation is a concept with three core dimensions, including “emotional support”, “Online contribution” and “charitable action”, which can be effectively measured through 16 items.