The treatment of major depressive disorder（MDD）comorbid with chronic pain has always been a central issue in clinical practice. Scientists have explored its etiology and pathogenesis and found that the complex interaction between pro-inflammatory factors and anti-inflammatory factors is considered to be the key to the occurrence， development and prognosis of MDD comorbid with chronic pain. This review summarizes the mechanism of inflammatory factors in MDD with chronic pain， and prospects the development direction of drug treatment in this kind of disease in the future.