1.Mass puncture examination: mass puncture biopsy for pathology examination can help to determine the diagnosis of plasmacytoma.2.Blood and urine examination: blood and urine examination is needed at the initial diagnosis, which is used to detect monoclonal immunoglobulin cells in serum or urine to help to make the diagnosis. Specific test indicators may include blood and urine immunofixation electrophoresis; serum free light chain; hemoglobin; blood creatinine, creatinine clearance; blood calcium; lactate dehydrogenase, serum protein. Serum globulin is increased in most cases, and the albumin/globulin ratio is inverted. In a few cases, serum electrophoresis has no manifestation, while urine electrophoresis has manifestation.3. Imaging: Imaging is helpful in determining the extent of the lesion, and patients with plasma cell tumors are seen on X-ray as tiny wormlike, rounded punctate osteolysis, foamy after fusion of osteolytic areas, and extensive osteolytic lesions in advanced stages.PET-CT not only detects skeletal lesions, but also screens for extramedullary plasmacytomas, and provides the level of tumor Metabolic level, is one of the most efficient means.4. Bone marrow examination: Bone marrow aspiration and biopsy can clarify the presence of abnormal plasma cells, which is one of the important indicators to clarify the diagnosis of multiple myeloma. When the diagnosis of plasma cell tumor is not clear at the early stage, bone marrow smear can often confirm the diagnosis, but negative can not exclude the possibility of plasma cell tumor, and the examination of chromosome and other genetic material can help to predict the effect of treatment as well as the prognosis of the disease.