The modular self-reconfiguration robot is composed of several standard models. By using sensors configured in the standard model to obtain the operating environment and relevant information, and by using the connectivity and interchangeability between models, the cross movement, connection and separation between models can be used to change the configuration, enriching the function and motion form. Modular self-reconfigurable robot. It has the characteristics of complex and changeable structure, rich and diverse motion models and reconfigurable target configuration. In this paper, the existing key technology of modular self-reconfigurable robot connection structure is reviewed, and the physical principles and basic structures of three different connection structures of self-reconfigurable robot are summarized. This paper focuses on the recent research results of mechanic-electromagnetic self-reconfigurable robot connection structure and related hot issues, including the speed of self-reconfigurable robot reconstruction and reconstruction algorithm and other hot issues. Finally, the development prospect of the key technology of the self-reconfigurable robot is prospected, and the key technical problems that need to be solved are discussed.