Multiple myeloma,the second most common malignancy of the blood system,is a malignant clonal proliferative disease of plasma cells.The main clinical manifestations are increased blood calcium,renal impairment,anemia,bone damage,and secondary amyloidosis.Although there are many clinical approaches available for multiple myeloma,there is no cure for the disease,and most patients eventually relapse.The introduction of immunomodulatory drugs has significantly improved the survival outcome of patients with multiple myeloma and is a cornerstone of the treatment of multiple myeloma patients throughout every stage of treatment.This article discusses the mechanism of action of immunomodulatory drugs and summarizes the current application of immunomodulatory drugs in the clinical treatment of multiple myeloma.