The Yangchang phosphate deposit in Zhenxiong County,Yunnan Province is a super large sedimentary phosphate rock deposit discovered in recent years in the Early Cambrian period. It has the characteristics of "large resource reserves, excellent ore quality, and concentrated resource distribution", and is currently the largest hidden single rich phosphate deposit in Asia. This article uses automatic quantitative analysis system for mineral parameters (AMICS), scanning electron microscopy energy dispersive spectroscopy (SEM-EDS), X-ray fluorescence spectrometer (XRF), inductively coupled plasma mass spectrometry (ICP-MS), and polarizing microscope analysis methods to systematically study the chemical composition, mineral composition, embedding characteristics, particle size and occurrence status of major minerals, and mineral dissociation degree of the phosphate rock ore in the deposit. Research has shown that the ore belongs to a typical mixed carbonate type phosphate rock ore, with carbonate type as the main mineral. The ore mineral is collophane, and the vein mineral is mainly quartz, calcite, dolomite, and a small amount of pyrite. The embedded particle size of phosphate rock is relatively large, and many particles belong to a high degree of freedom state with a dissociation degree greater than 75%, which is easy to dissociate. However, the monomer dissociation degree is low, and there is no significant increase in monomer dissociation degree with the increase of fragmentation degree. Vein minerals such as quartz, calcite, dolomite, and pyrite have smaller particle sizes and lower monomer dissociation. The degree of monomer dissociation of mineral particles increases significantly with the increase of sample fragmentation. If mineral processing methods are needed to remove vein minerals, grinding time should be appropriately increased to increase their monomer dissociation degree. Colloidal phosphate ore is mainly associated with minerals such as quartz, calcite, and dolomite in two or multiple phases.Based on comprehensive analysis of mineral composition, particle size distribution, and mineral association, the main method for ore selection is desilication, followed by magnesium removal. It is recommended to use "positive flotation" for desilication. If "positive flotation" cannot meet the requirements of phosphorus concentrate indicators or the recovery rate is low, "positive reverse flotation" can be used for desilication first and then magnesium removal to achieve better separation results.