Research infrastructure (RI) refers to a large and complex science research facility or system that conducts top-level science activities. In recent years, there has been a tendency toward geographical concentration of RIs and formation of RI clusters. Some of these RI clusters have become engines for regional social and economic development. It turns out that RI clusters present a new stage for RI sustainable development. The present paper tries to study RI clusters based on symbiosis theory in order to build an analytical framework for policy makers’ comprehensive understanding of RI clusters. Following the analytical framework, we study the symbiosis system and the symbiosis structures of an RI cluster by analyzing its major characteristics. In order to achieve a balanced symbiotic situation, a competitive model and a symbiosis model are proposed based on the Logistic Model. The analysis is grounded in the samples of China’s typical RI clusters and other cases in the world to give a vivid and convincing illustration. During the analysis process, an RI cluster is regarded as a complex ecological system and the organization and management of units in the cluster is the focus of the study. The authors hope that the paper will supplement the existing literature, which mainly focuses on the technological problems and the evaluation of RI’s socioeconomic effects, in the sense of a systematical analysis of the management problem of RI.