Abstract: Through comparative studies of different digestion methods for five ore samples with varying grades collected from adjacent mining areas in Yunnan and Guizhou Provinces, combined with optimization of instrumental parameters and accuracy precision tests of analytical methods, this research systematically investigated the analytical techniques for associated elements (Nb, Zr, Ga, Sc) in sedimentary rare earth ores. A preliminary exploration of their distribution patterns during selective leaching processes was also conducted. The results indicate that high-pressure sealed acid dissolution combined with ICP-MS analysis achieved excellent performance, with relative standard deviations (RSD) below 5% and recovery rates ranging from 96.2% to 103.6% for all target elements (Nb, Zr, Ga, Sc), demonstrating high precision and accuracy of the proposed method. Furthermore, selective leaching experiments revealed a strong positive correlation between the leaching behaviors of Al₂O₃ and Ga₂O₃, which provides valuable guidance for the comprehensive utilization of gallium in sedimentary rare earth ores.