The pulse forming network (PFN)-Marx generator can realize both integration of pulse modulation and pulse voltage accumulation, exhibiting a the natural “gene” of compactness. In recent years, the pulsed energy storage technology has been developing rapidly, which makes it a reality to use PFN-Marx generators to drive various loads directly. The PFN-Marx generator has gradually become a worldwide research focus. The research progress of high-power compact PFN-Marx generators are systematically introduced in this paper. In summary, judging from the development over time, PFN-Marx generators adopt high-energy-density components and thus improve the energy density level themselves, which makes the generator more and more compact. In the pursuit of compactness, the effect of optimal design of PFN-Marx generator spatial structure is better than optimal design of PFN network topology parameters. The waveform optimization method of the PFN-Marx generator has obvious benefits, which can effectively reduce the negative impact of stray parameters strongly coupling between stages caused by small size of generator. In the meanwhile, this paper discusses the development trend of PFN-Marx generator.