Monocytes are important innate immune cells of the body, which can phagocytose and remove injured and senescent cells and their fragments, and participate in the immune inflammatory response of the human body. Monocytes can further differentiate into macrophages and dendritic cells, both of which play an important role in establishing an effective immune response. Monocytes, macrophages and dendritic cells are widely used in related research in basic and clinical medicine. This article will introduce several different methods for isolating monocytes from peripheral blood, and compare and analyze their advantages and disadvantages, so as to help researchers choose a suitable separation method to efficiently obtain monocytes that meet the experimental requirements, and lay the foundation for subsequent research.