Objective To explore multiple myeloma in X-ray, CT , MRI and 18F-FDG PET/CT performance, improve the understanding of multiple myeloma in imaging. Methods 55 cases confirmed by pathology and clinical patients with multiple myeloma imaging data were retrospectively analyzed. Results X-ray of 94 cases in 110 cases with abnormal 62 cases, the diagnosis coincidence rate 65.9%, CT 90 cases, 82 abnormal cases, the diagnosis coincidence rate 91.1%. MRI36 example, there are 34 cases, abnormal diagnosis coincidence rate 94.4%, 18F-FDG PET/CT15 cases, 14 cases have abnormal, diagnostic coincidence rate was 93.3%. Four inspection methods for multiple myeloma diagnosis coincidence rate between the difference was statistically significant (χ2 =26.18, P<0.05), and X-ray diagnosis coincidence rate is lower than the other three kinds of inspection, the difference was statistically significant (χ2 =25.98, P<0.05), CT, MRI and 18F-FDG PET/CT three test results no statistical differences (χ2 =0.43, P>0.05). Multiple myeloma X-ray and CT main show is sparse, bone expansion and destruction, with pathological fracture and soft tissue mass, a few bone sclerosis; MRI of T1WI low signal, for high T2WI signal, a typical cash as the "salt and pepper". 18F-FDG PET/ CT performance for matching the high 18F-FDG uptake stove and bone dissolve osseous changes. Conclusion Multiple myeloma has characteristic imaging findings, three inspection methods have their own advantages, to know and understand its imaging findings, plays an important role in diagnosis of multiple myeloma.