To study the development status and technical problems of the emerging spacecraft cluster network, this paper analyzes the latest literatures in this field. Spacecraft cluster is a kind of novel multiple spacecraft collaborative work framework, which performs information interaction via wireless links and serves to the increasingly complex and diverse space exploration missions in the future. First, this paper makes the concept of spacecraft cluster network clear by involving the definition of satellite cluster. Then, it analyzes the current status and development course of the distributed space exploration missions as well as describes the spacecraft cluster network from the perspective of theory and orbital dynamics. Finally, it summarizes the key technical problems when studying spacecraft cluster network, including topology control strategies, data routing algorithm, space inter-communication protocol, cross-layer resource allocation algorithms. It also puts forward some corresponding suggestions of development. The result shows that technologies in spacecraft cluster network are still at the initial stage, and several key technical problems need to be solved. Some mature networks, e.g., Internet and Mobile Sensor Network, can serve as technical reference models for the breakthrough of these problems.