This paper proposes a miniaturized impulse voltage generator that differs from the traditional gas ball gap. It adopts a modular multi-stage structure, using the Marx topology as the main circuit and MOSFET as the main switch. MATLAB is used to fit and modulate lightning impulses or chopped lightning impulses through the nearest-level forced modulation algorithm (NLM). an FPGA controls the modular impulse voltage generator to generate impulse voltage waveforms such as charging voltage, wavefront time, wave tail time, and truncation time, all of wich can be flexibly adjusted by the host computer. The test results show that the maximum output voltage of a single impulse voltage module is 24 kV, with a total of 30 stages of voltage output. When 5 impulse voltage modules are operated in series, a maximum of 150 stages of different voltages can be generated, and the peak voltage can reach -100 kV lightning impulses or chopped lightning impulses.