With the increasing application of high voltage direct current transmission (HVDC) in cross regional transmission of new energy, new energy units at the transmission end may not only suffer from voltage dips and high voltage faults, but also face challenges of low and high voltage disturbances caused by DC commutation failures. In order to accurately analyze the impact of wind farm integration on the power system, a four-machine equivalent method was proposed based on doubly fed induction generator (DFIG) to adapt to multiple types of faults at the DC transmission end. Firstly, the general power curve of wind turbines was modeled for low voltage ride through, high voltage ride through, and continuous low and high voltage ride through in accordance with national standards. Next, the single machines that suffer from multiple types of faults from the cut in wind speed to the cut out wind speed was traversed, and the wind turbines in the wind farm was clustered. Finally, a four-machine equivalence method is proposed based on simulation results.