A two‐stage macrophage regulatory mechanism involving NIR external field‐induced M1 macrophage death and catalase/superoxide dismutase‐like activities‐mediated polarization of pro‐inflammatory M1 to anti‐inflammatory M2 macrophages through the folic acid‐mediated active targeting pathway, promising a new insight for efficient and safe rheumatoid arthritis treatment. Here, CAT is linked to rheumatoid arthritis.