Abstract: In this paper, the harm, occurrence and rule of the main impurity sesquioxide （R₂O₃） in phosphate ore to the downstream production are summarized, and the separation method and research progress of sesquioxide are discussed in detail. With the increasing scarcity of resources, the increase in the content of sesquioxides in the flotation concentrate of phosphate ore will lead to the decrease of the decomposition rate of phosphate ore and the decrease in the activity of acid hydrolysis reaction, which will lead to the decline in the quality of phosphoric acid products produced by the downstream phosphorus chemical industry, the scaling of pipelines and the difficulty of transportation, and so on. It is urgent to constantly study new methods of phosphorus ore semisoft removal. At present, the main methods of sesquioxide removal include flotation separation, maglev flotation, fractional flotation and other combined flotation methods, chemical separation and so on. Flotation can effectively remove part of the content of sesquioxide. Future research direction is mainly to develop more selective and targeted agents for removing iron and aluminum. Maglev separation is mainly used to remove iron gangue minerals in phosphate ores, and fractional flotation is mainly used for phosphate ores with more clay minerals. Chemical law is mainly aimed at aluminum gangue mineral treatment, solvent extraction method is the main research direction of aluminum removal in the future. Whether flotation or chemical methods, a single method is difficult to deal with the phosphate ore to qualified phosphorus concentrate requirements, so the flotation and downstream chemical industry will be more closely linked.