A control strategy for DFIG wind farm low votage ride through based on VSC-HVDC is proposed.In accordance with the model of DFIG and VSC,the limitation of reactive power is calculate. When the system break down, traditional Crowbar circuit will make a short circuit in RSC which make DIFG unable to provide reactive power to the system.A improved control strategy is proposed so that the Crowbar circuit will act according to the level of the fault. In consideration of the power limitation of each convertor station, the strategy of reactive power distribution is put up which will allot the reactive power output according to the reactive power gaps of the system.A model is established using MATLAB/Simulink to verify the improved strategy.