The invention discloses a high-voltage pulse generator suitable for a time-of-flight mass spectrometer. The high-voltage pulse generator comprises a DC high-voltage high-speed switch, a first voltage input terminal IN1, a second voltage input terminal IN2, an impulse voltage output terminal OUT1 and a rear substrate voltage output terminal OUT2. The advantages of the high-voltage pulse generator are that the high-voltage pulse generator adopts a low-complexity circuit design; a 10KV impulse voltage is superposed on a 30KV substrate voltage, and the width of a falling edge of the impulse voltage is controlled to be about 200ns; and the width of the impulse voltage is smaller than 10 mus, thereby meeting actual demand that ions need to stand for several hundred nano seconds after overflow due to obtaining laser energy, greatly improving ion transmission and system sensitivity, and meanwhile, effectively reducing manufacture cost of the time-of-flight mass spectrometer.