Abstract: The type of magnetite ore belongs to the altered gabbro type iron mine in Guazhou County, Gansu Province. The chemical and mineral properties were studied by means of chemical multiple analysis, X-ray fluorescence spectrum analysis, phase analysis, microscopic identification and particle size determination and the mineral processing test was carried out. Its mineral composition and content, mineral distribution characteristics and occurrence state of iron were found out through systematic process mineralogy research. The study of ore composition shows that the magnetite ore is mainly calcite chlorite altered gabbro, followed by calcite actinolite altered gabbro. The main useful minerals in the ore are magnetite and hematite, a small amount of altered pyrite and titanomagnetite, and the particle size of magnetite is mainly fine. Gangue minerals are widespread and complex, mainly chlorite, calcite, quartz, actinolite, plagioclase, and secondly amphibole, pyroxene, etc. In this paper, mineral processing tests are carried out to confirm the research results of process mineralogy, which provides an important reference for the evaluation of iron mine and the comprehensive development and utilization of resources in this area.