Research on the effect of pulsed electric field in cell electroporation attracts more attention, especially tumor ablation. This puts forward higher requirements for pulsed electric field parameters. The shape of the pulse waveform was also required in different electroporation applications. Based on this, a multilevel pulse generator with series capacitor structure was proposed in this article. Besides, it can also obtain the different shapes of the pulse waveforms by controlling the timing of semiconductor switches. The voltage amplitude, the number of pulses, and the pulsewidth are all adjustable. A ten-level test prototype with 11 switches was built. The structure was simple and was more compact. It can work stably under the simulated small resistance load. Finally, when the dc charging voltage was 1 kV, the system can achieve a maximum output voltage of ±500 V. The number of pulse in one pulse sequence was 1–500. The pulsewidth was adjustable from 1 to $10~\mu \text{s}$ . By controlling the switch’s timing, it can also obtain the multilevel voltage output, exponential waveform voltage output, and composite waveform output combined narrow pulse with wide pulse.