Abstract: With the development of offshore wind power from nearshore to deep offshore construction, harmonic resonance has become one of the problems affecting the stability of the power grid. The harmonic amplification mechanism of offshore wind farms was analyzed, and a harmonic model of offshore wind farms was established. The harmonic resonance analysis method of “frequency scanning+modal analysis+on-site measurement” was adopted to simulate and verify the influence of different system parameters and wind turbine operating conditions on harmonic resonance. This has guiding significance for offshore wind engineering design and grid connected power generation work.