Macrophages are important components of the immune system and play a core role in immune regulation and tissue repair. Macrophages are plastic cells that can polarize into many subtypes with different functions under different stimuli. Macrophages in different polarization states play crucial roles in disease development and prognosis. In-depth studies of macrophage polarization contribute to exploring new strategies for disease prevention and treatment. In this article, we summarize the different polarization phenotypes and main functions of macrophages under different microenvironmental signal stimuli, focusing on the role of macrophage polarization in the tumor, atherosclerosis, and type 2 diabetes, as well as the therapeutic strategies targeting macrophage polarization.