The invention provides a novel enclosed multi-ball electrode ignition device, comprising a multi-ball electrode assembly, a voltage-sharing assembly and an air chamber assembly. The multi-ball electrode assembly comprises an epoxy capacitor bar and a voltage-sharing resistor; the epoxy capacitor bar is provided with copper sheets in a surrounding manner at an equal interval; the multi-ball electrode assembly comprises hemispherical electrodes which are fixed on the copper sheets, and a small ball gap is formed between two adjacent hemispherical electrodes; the air chamber assembly comprises conductive sheets, and an inlet valve and an exhaust valve which are arranged on a seal air chamber; the multi-ball electrode assembly and the voltage-sharing assembly are arranged in the seal air chamber; and the conductive sheets are arranged at the two ends of the epoxy capacitor bar for leading electrodes at two sides of the ignition device out of the seal air chamber. Compared with the prior art, the novel enclosed multi-ball electrode ignition device solves the problem of self-discharge or non-discharge which is easy to occur in the conventional ignition device of the impulse voltage generator, and remarkably improves the reliability of the ignition, and improves the voltage output efficiency of the impulse voltage generator.