Virtual synchronous generator (VSG) technology is the new generation renewable energy power generation technology that transforms it from “passive regulation” to “active support”, that is an effective path to make the renewable energy power generation have the ability to active support the power grid with inertia support, primary frequency regulation and active voltage regulation, and the virtual synchronous generator technology is an exploratory practice for solving the problems of “double-high” power system. The control modes of voltage-controlled and current-controlled of virtual synchronous generator, the operating characteristics of current control, voltage control and improved virtual synchronous generators are summarized, and the comparative advantages and shortcomings are analyzed with the view of technical principles. Focusing on the stability analysis problems and transient control of the grid-connected virtual synchronous generator, the common stability analysis methods are summarized, and the current research on the influence on the power system stability and oscillation of grid-connected improved virtual synchronous generators is summarized. On this basis, the research keys of virtual synchronous generator stability analysis, oscillation suppression and fault voltage ride-through are pointed out. Finally, the interaction mechanism and dynamic stability improvement technology of improved virtual synchronous generators are prospected, and the key problems of follow-up research are pointed out, and the referenced solution paths are proposed.