The invention relates to a fault ride-through method and device for a passive sending system in a flexible DC power grid. The method includes the following steps: putting a bidirectional thyristor switch into operation according to the operation status information of a new energy power generation passive sender converter station or a flexible DC power grid to connect a PCC point on the AC side ofthe new energy power generation passive sender converter station with the ground, and making a safety and stability control device remove the generation power of a new energy power generation passivesender; and making the bidirectional thyristor switch disconnect the PCC point on the AC side of the new energy power generation passive sender converter station from the ground. According to the technical scheme provided by the invention, a control method based on coordination among the parallel thyristor switch, the safety and stability control device and the passive AC power grid protection ispresented, which can limit the active power flowing into the passive sender converter station in the process of disturbance accidents in a flexible DC power grid passive sender converter station, a receiver converter station and a receiver AC power grid and realize safe and efficient ride-through of the faults by the flexible DC power grid.