Abstract: Grid-forming converters are received much attention in scenarios such as renewable energy DC transmission, weak grid, and microgrid due to their synchronous voltage source operation characteristics. Power synchronization control is one of the typical controls for grid-forming converters. However, since the nonlinear and multi-loop control characteristics of power electronics, the issues of multi-VSCs interaction and stability of the grid-forming converters with power synchronous control can not be ignored. The paper reviews and summarizes the technologies of multi-VSCs interaction analysis and stability controls for grid-forming converters with power synchronous control. Firstly, the stability issues of multi-VSCs for grid-forming converters are classified as active power oscillation and transient synchronization instability, and the corresponding models and analysis methods are reviewed, respectively. Secondly, the existing stability controls for the two types of stability issues are separated into the perspectives of unit control and system control. Finally, the research results and limitations of existing research are summarized, and the prospects in researches in the future are put forward.