The invention relates to a high-voltage series resonance device and a voltage withstanding test method using the device. The high-voltage series resonance device comprises a variable-frequency power source cabinet, a testing transformer, a resonance electric reactor and a testing voltage measuring device with a current sensor, wherein the current sensor is connected in series between the high-voltage end tail and the grounded end of a capacitive sample; the resonance electric reactor is installed with a fixed section number at a fixed position, so that the inductance value of the resonance electric reactor remains unchanged. The frequency of voltage signals output by the variable-frequency power source cabinet is adjusted through the device, so that when a series resonance circuit is in a complete resonance state, the voltage value of the resonance electric reactor is equal to that of the two ends of the sample to be tested, and sample test voltage to be detected is determined through Fourier transform. It is unnecessary to arrange a high-voltage bleeder special for measuring the test voltage, so that a voltage withstanding test is completed efficiently, safely and conveniently, and it is ensured that test voltage accuracy is within an allowed range, and safety and working efficiency of the high-voltage series resonance alternating-current voltage withstanding test are improved substantially.