Heap leaching technology for gold extraction holds an irreplaceable role in utilizing low-grade gold resources due to its economic efficiency and high effectiveness. Comminution particle size is a critical operational parameter in gold ore heap leaching, directly influencing leaching efficiency and production costs. Excessively coarse particles reduce leaching effectiveness, while overly fine particles increase energy consumption, compromise economic viability, and degrade permeability, further diminishing leaching performance. This study synthesizes the impact ofparticle size on leaching efficiency, permeability, and cost, reviews recent advancements in optimizing comminution particle size for heap leaching, and discusses factors affecting particle size selection, including ore properties, leaching agent types, and leaching conditions. Future research directions emphasize optimizing particle size distribution, controlling leaching costs, and synergistically improving other leaching parameters, aiming to provide guidance for enhancing low-grade gold ore heap leaching processes.