The invention relates to a test device for detecting the resistance of a high-voltage direct-current transmission converter valve. The test device comprises a power supply circuit, a resonant circuit, a boosting rectification circuit, a damping capacitor C, a resistor R1 and a thyristor, wherein the power supply circuit provides electricity for the whole device; the resonant circuit converts the voltage into a resonance current and then transmits the resonance current to the boosting rectification circuit for rectification; the output current subjected to the rectification is used for charging the damping resistor C; and the thyristor is triggered at an appropriate moment to ensure that the thyristor is conducted so as to test the resistor R1. By the test device, the current impact received by the damping resistor under an actual working condition and the power consumed by the damping resistor are equivalently simulated; and the test device is simple in topology structure, is flexible to control, convenient and quick to control, and convenient to adjust parameters, and can meet test requirements in a stable state and a transient state. The resonance current of the test device is sinusoidal and is in a discontinuous conduction mode, so the test device has soft switching characteristics of zero-current turn-on and turn-off, the switching loss is greatly reduced, and the efficiency of the device is high; and the test device can realize a high repetition frequency and frequency switching in operation.