It is important to understand the creative processes of social value networks in terms of the interdependent connections between fashion sharing economy businesses and consumers. In particular, when the similarity in the values of each member is shared in the sub-network, the closeness of the relationships can be further strengthened. In such value chains, the overall process is important because the content, which is originally provided through the distribution process, is reinterpreted from the consumer’s point of view and it is reproduced as new creative output with high added value. In this study, the characteristics of sub-network structure, the characteristics of social relations, and network externality are proposed and analyzed as influential variables of information diffusion behaviors that explain the diffusion of shared information in fashion sharing economy platforms. We examined the shared information diffusion performance of the sharing economy platform as a multidimensional influential factor including the network characteristics, and proposed a structural model that integrated network research and mobile information diffusion research. We surveyed 400 people with experience of fashion information activity on sharing economy platforms. Frequency, validity, reliability, measurement model and path analyses were conducted using SPSS and AMOS statistical packages. The results showed that trust value, profit/risk sharing, interdependence, and cultural/social similarity of the sub-network structure characteristics affected social relations, while trust value and cultural/social similarity also influenced relational embeddedness. Social relations and relational embeddedness, in turn, affected perceived complementarity and social interaction, both of which affected fashion information diffusion behaviors. Finally, social pressure, social ties, and social unity affected trust values. The results of this study can be applied not only to social connections among the members of the sub-network of a fashion sharing economy platform, but also as an effective means to explain the maintenance and reinforcement of mutual relations, thereby advancing the current academic research and practical applications.