In order to meet the accurate and efficient simulation requirements of large-scale AC/DC power grid multi-time scale dynamic processes, research has deeply discussed multi-time scale partition simulation methods combining different simulation modeling theories. For multi-time scale partition simulation, the simulation interface between different partitions is the key to determining the success or failure of the simulation. Firstly, the multi-time scale characteristics of the AC/DC power grid and the classification of partitioned multi-time scale simulations are analyzed. Then, the key issues in the design of the electromechanical-electromagnetic transient offline simulation interface are summarized. Furthermore, the research status of multi-rate electromagnetic transient simulation interfaces and frequency shifted conventional electromagnetic transient hybrid simulation interfaces is summarized. Finally, future research directions for the design of multi-time scale partition collaborative simulation interfaces are discussed.