Abstract: In the context of high-scale integration of renewable energy, virtual synchronous machine(VSM) control technology—a sophisticated method simulating the electromagnetic and mechanical dynamics of synchronous generators—has emerged as a critical approach to enhance grid-connected performance and transient stability. This study investigates the VSM control architecture, analyzing its dynamic response mechanisms during voltage sags. Through systematic modeling of frequency response characteristics, voltage sag control strategies, transient power regulation behaviors, and control parameter sensitivity, multi-scenario system tests validate the VSM′s dynamic stability and engineering applicability in voltage sag mitigation scenarios.