Abstract: The multi-element and XRD diffraction analysis of a magnesite in Xinjiang shows that the main component of the ore is MgO, which exists in the form of magnesium carbonate, and the gangue minerals are quartz, dolomite, calcite, etc, which are considered as fourth industrial grade products. Pre-sludge-reverse-direct flotation of ore, reverse flotation under the conditions of grinding fineness of -74 μm 79.8%, pulp pH=6, water glass dosage of 500 g/t, octadecylamine 300 g/t, The concentrate grade is 44.21%, the operating recovery rate is 91.17% of crude concentrate, and then the slurry pH=9, inhibitor 150 g/t, 2# oil 100 g/t, collector YSM-091 is 1500 g/t, Under the conditions of flotation, the concentrate grade of magnesium is 46.31% and the recovery rate is 91.23%. Under the best conditions, a closed circuit test can be carried out to obtain a final concentrate product with a concentrate grade of 46.12%, with a comprehensive recovery rate of 77.83%, and the main impurities SiO₂ and CaO have a grade of 0.92% and 0.81%, respectively. Compared with the technical indicators of magnesite grade, the concentrate product meets the first grade requirements in the industrial grade.