Abstract: The integration of large-scale offshore wind farms into onshore power grids via voltage source converter based multi-terminal direct current (VSC-MTDC) increases the proportion of uncertain power sources in the system, which raises the difficulty of coordinated control for system frequency regulation resources and affects the frequency security and stability of regional power grids. To address the above issues, a hierarchical distributed coordinated control strategy based on the consensus algorithm is proposed for frequency support of VSC-MTDC integrating offshore wind farms. For the onshore converter stations, the control law of their active power commands is designed with the frequency of different onshore power grids as the consensus index. On the premise of ensuring the frequency security of onshore power grids without frequency disturbances, the onshore converter stations can provide as much active power support as possible to the disturbed onshore power grids. For the offshore wind farms, the control law of their droop coefficient for offshore wind farms is designed with the ratio of active power variation to the maximum frequency regulation capacity of offshore wind farms as the consensus index. It realizes the reasonable allocation of frequency regulation power among offshore wind farms with different frequency support capabilities. The simulation verification is carried out on a three-sending and three-receiving VSC-MTDC system integrating large-scale offshore wind farms. The simulation results show that the proposed control strategy can fully exploit the mutual frequency support capability of different onshore converter stations and the frequency support capability of different offshore wind farms, effectively improving the frequency stability of onshore regional power grids.