Abstract: Electrode Induction Melting Gas Atomization (EIGA) has emerged as the mainstream powder preparation technique for additive manufacturing (AM), by virtue of its distinct advantages including a narrow particle size distribution, high powder sphericity, and exceptional purity. Non-restricting atomizing nozzles play a decisive role in governing the atomization flow field characteristics and melt breakup efficiency, and structural optimization of such nozzles can effectively enhance both powder quality and atomization efficiency. Accordingly, this study first adopts numerical simulation to investigate the influences of three core structural parameters of the atomizing nozzle on the gas-liquid interaction throughout the atomization process, especially the gas channel inclination angle α, gas channel width d, and melt channel extension length L. The simulation results demonstrate that increasing the gas channel inclination angle expands the primary atomization zone yet reduces the peak gas velocity within this region. Similarly, a wider gas channel also enlarges the primary atomization zone; however, an excessive channel width compromises the suction pressure at the nozzle outlet, impeding the outflow of molten metal and even triggering melt backflow. Moreover, a longer melt extension length diminishes the primary atomization zone, while the peak gas velocity in the secondary atomization zone initially increases and subsequently decreases.