The invention relates to a converter valve thyristor voltage-equalizing element test device and method. The device comprises a test signal source module, an acquisition and processing module and an element parameter calculation module, wherein the positive output end and the negative output end of the test signal source module are connected to the positive input end and the negative input end of athyristor level respectively; the positive input end and the negative input end of the acquisition and processing module are connected to the positive output end and the negative output end of the thyristor level respectively; the output end of the acquisition and processing module is connected to the input end of the element parameter calculation module; and the test signal source is used for generating test voltage of direct current and different frequencies of alternating current. By applying the test voltage at the two ends of the thyristor level, voltage and current values of a thyristorvoltage-equalizing loop at a certain frequency can be measured; and then, through a Newton-Raphson algorithm, a parameter value of a voltage-equalizing element is calculated. Compared with the priorart, the device and method are short in test time and simple in test process, and can effectively improve test efficiency.