Abstract: Taking a kaolin ore in Yunnan Province as the research object, a systematic process mineralogy study was carried out by XRD, XRF, optical microscope, scanning electron microscope (SEM) and electron probe microanalyzer (EPMA). The results showed that the mineral composition of the kaolin ore was mainly kaolinite, quartz and a small amount of muscovite. The yield of kaolin-0.045 mm class was 55.72%. After classification, kaolinite was mainly enriched in -0.020 mm classes. The morphology of kaolinite was mostly laminated or wormlike, and a small amount was tubular. Whiteness increased from 63.96% to 85.92% after calcination. Iron and titanium impurity elements mainly occur in independent minerals such as hematite and rutile. Through simple classification and purification, kaolin ore can meet the relevant standards of ceramic industry and rubber and plastic industry.