In recent years, offshore wind power has emerged as a critical frontier in global wind energy development, driven by its stable resource conditions, high utilization rates, proximity to load centers, and minimal land use. For offshore wind farms located near the onshore grid with smaller capacities, alternating current (AC) integration is typically employed. However, as these wind farms scale up and transmission distances increase, the voltage source converter-based multi-terminal high-voltage direct current (VSC-MTDC) system has gained prominence. This system effectively addresses challenges related to clustering, long-distance transmission, and multi-regional grid integration of wind energy. Despite its advantages, the VSC-MTDC system’s characteristic of decoupling offshore and onshore AC systems poses challenges in frequency support. Frequency fluctuations in the onshore system prevent direct support from offshore wind power, potentially compromising overall power system stability and safety. Therefore, comprehensive research on active frequency support control strategies for VSC-MTDC-connected offshore wind farms is essential to ensure the secure and efficient integration of large-scale offshore wind power.