This study aims to optimize the comminution process in light of the characteristics of fine embedded size and easy sliming of valuable minerals in complex rare-earth ores to achieve efficient grinding of the complex rare-earth ore. Firstly, taking a rare-earth ore from China as the research sample, the process mineralogy and crushing working index tests were conducted to explore the properties of the ore. Subsequently, crushing tests were conducted respectively using jaw crushers, double-roll crushers and high-pressure grinding rolls, and grinding tests were conducted using ball mills and rod mills. The particle size distribution, the liberation degree of gangue minerals and the microscopic morphology of different products were compared and analyzed. Finally, magnetic separation test was carried out, and the magnetic separation performance and energy consumption of different grinding products were compared and analyzed. The results show that HPGRs have higher crushing efficiency and produce more suitable particle size distribution of the product. Rod mills have the selective grinding effect on coarse-grained particles and the selective protection effect on fine-grained particles, which can effectively reduce mineral sliming formation and increase the recovery of the magnetic separation process under the similar concentrate grade. This research has certain guiding significance for solving the crushing and grinding problems of complex rare-earth ores, and can provide a reference for the efficient development and utilization of this ore type.