The invention discloses a method and a system for acquiring the measure amount of the locking fault of a flexible direct current grid converter, which belongs to the technical field of power system safety and stability control. The method provided by the invention comprises the steps that a topology structure of a flexible direct current grid safety control system is determined; the calculation data of the measure amount of the locking fault of the flexible direct current grid safety control system converter are acquired according to the topology structure; the calculation variable of the measure amount of the locking fault of the flexible direct current grid safety control system converter is defined according to the locking fault of the converter; and the measure amount of the locking fault of the converter is acquired according to the calculation data and the calculation variable. According to the invention, when the flexible direct current grid safety control system has the lockingfault of the converter, the safety control system thereof can calculate the correct fault measure amount; and safe and stable operation of the flexible direct current grid can be effectively ensured.