a direct-current high-voltage generator;

a high-voltage switch, a high-voltage capacitor bank;

an isolation transformer, an energy absorption device; and

a high-voltage sphere gap short-circuit switch,

wherein the direct-current high-voltage generator charges the high-voltage capacitor bank through the high-voltage switch and stores electrical energy, and at this time, positive electrode potentials of the high-voltage switch, the high-voltage capacitor bank, a secondary side of the isolation transformer, the energy absorption device and the high-voltage sphere gap short-circuit switch are consistent with that of the direct-current high-voltage generator; when the high-voltage capacitor is charged to the same level as a test voltage, the high-voltage switch is disconnected, such that the direct-current high-voltage generator is disconnected from a main circuit, and the high-voltage sphere gap short-circuit switch is triggered; at this time, the short-circuit current starts from a positive electrode of a pulse capacitor of the high-voltage capacitor bank, flows through the energy absorption device, and returns to a negative electrode of the high-voltage capacitor bank through the high-voltage sphere gap short-circuit switch, and the energy stored in the high-voltage capacitor bank is released; and finally, the energy absorption device is dismantled or short-circuited to repeat charging and discharging processes of the high-voltage capacitor bank, and short-circuit currents in the case of serial connection or not serial connection with the energy absorption device are compared, thereby implementing the verification of distributed capacitance energy absorption.