The pulse plasma discharge breakdown is a longstanding research topic in plasma physics, yet the formation process remains elusive. In this study, we investigate the breakdown process under nanosecond pulses with different pulse widths (1 ns, 10 ns, and 100 ns), utilizing the 1D implicit Particle-in-Cell/Monte Carlo collision (PIC/MCC) method. Our simulation results indicate that pulse width plays a crucial role in the evolution of plasma breakdown. Specifically, under 1 ns pulses, the breakdown occurs after the pulse voltage ceases, demonstrating that increasing pulse width accelerates the changes in plasma parameters but does not affect the breakdown time. Under 10 ns pulses, the removal of voltage leads to a significant increase in anode sheath thickness. Under 100 ns pulse, the ions collide in the cathode sheath after the pulse ends, resulting in ion energy loss. Finally, by scanning the parameter space, we give the Paschen curve and observe higher breakdown voltage in the pulse case and the impact of ion secondary electrons.