Nanosecond pulsed liquid discharge has attracted significant attention in various applications, in which adjustable parameters and compact volume of nanosecond pulsed power are essential for the convenience of researchers. In this paper, a compact volume (0.6 × 0.8 × 0.4 m3) nanosecond pulsed power supply is built for the liquid discharge with the capacity charging power supply technology. Moreover, a high-frequency induction feed control system is adopted to achieve synchronizations between insulated gate bipolar transistors to realize the adjustable pulse width and frequency. A non-inductive resistor is used to test the properties of the nanosecond pulse power supply, and results show that the rising time of nanosecond pulse power is 100 ns with the pulse width in the range of 4 µs to ∼100 µs, and the output pulse voltage and repetition frequency are 0 kV–20 kV and 1 Hz–300 Hz, respectively. Moreover, the needle-to-needle electrode discharge in the liquid phase is successfully excited by this power supply with different working conditions.