Abstract: Objective In Sichuan, the iron, manganese and phosphorus polymetallic ore is taken as the research object. During the test, there are many problems, such as serious mineral weathering, too many types of iron, manganese and phosphorus minerals, and extremely fine particle size. At the premise that the conventional mineral processing method is completely ineffective, Method a combined process of suspension roasting-leaching manganese-magnetic separation-floating phosphorus is designed. In this process, the iron and manganese elements are reduced by reduction roasting, and the manganese and iron elements are recovered by the manganese leaching-magnetic separation process. Apatite minerals were recovered by the desliming-flotation process. The process combines desliming and separation in parallel : suspended roasting removes very fine materials, the manganese leaching operation dissolves some fine-grained minerals and abandons the magnetic separation of the ore carried out part of the fine mud. Finally, the phosphate concentrate product is obtained by desliming-flotation, and gradually desliming and grading separation are carried out in manganese leaching, magnetic separation and flotation operations to ensure the feasibility and stability of the process.Result The leaching rate of manganese in the manganese leaching solution obtained by the above process reaches 91.37%, the grade of iron concentrate is 60.97%, and the recovery rate is 49.73%. The grade of phosphate concentrate is 31.47%, and the recovery is 48.71%. Conclusion This process achieved excellent beneficiation and metallurgical indicators and realized the efficient recovery of iron, manganese and phosphorus resources.