<p>Step-rising voltage ignition pulses can improve the machined surface quality by adjusting the discharge gap through ignition voltage modulation. However, the process is often impaired by ineffective breakdowns, where the breakdown state fails to transition into a stable spark discharge, consequently reducing the effective discharge ratio and machining efficiency. To address this issue, this paper experimentally investigates the discharge characteristics of such pulses. High-speed imaging is employed to observe the single-pulse discharge process, analyzing the distinct plasma behaviors during the ignition and spark discharge stages. Parameterized experiments were conducted to explore the influences of electrical parameters on discharge behaviors. Based on the findings, the pulse generation strategy is refined, and a synchronous control method for the ignition module and the discharge current generation module is proposed. Comparative experiments demonstrated that the new pulse generation method can effectively suppress abnormal discharges, leading to a higher material removal rate, lower electrode wear, and improved surface roughness.</p>