To address the prominent issues associated with traditional mechanically stirred reactors, such as the tendency of forming localized flow dead zones at the bottom of the vessel, poor bubble dispersion, and uneven gas phase distribution, this study employs numerical simulation methods to analyze the characteristics of the gas-liquid two-phase flow field within the reactor. The study focuses on investigating the influence of the structural parameters of the gas distributor on gas phase distribution, fluid flow conditions, and gas-liquid mass transfer performance. The results indicate that the orifice diameter of the gas distributor has a significant impact on the distribution of the gas phase. While maintaining low shear stress level and avoiding damage to the growth of microorganisms or microbial communities in the ore leachate, reducing the orifice diameter can effectively improve bubble breakup and dispersion, enhance the uniformity of bubble distribution within the vessel, alleviate the problem of bubble stagnation in dead zones, and thereby increase gas hold-up and the volumetric oxygen mass transfer coefficient. The research findings reveal the mechanisms by which key structural parameters of gas distributor influence flow field characteristics and mass transfer performance, providing important theoretical references for the structural optimization of multi-phase reactors in fields such as mineral processing and biometallurgy.