Abstract: A copper sulfide ore contains 0.55 % of Cu and 5.21 % of S with very high content of pyrrhotite. On the basis of the process mineralogical study, grinding fineness of 65 % of minerals particle size is less than 0.074 mm. The process of "flash flotation -mixed flotation-mixed rougher concentrate regrinding" is adopted. The results show that copper concentrate with copper bearing of 20.84 % and recovery rate of 93.97 % can be obtained. Compared with field process, the sorting index of copper is improved to save the grinding cost.