Free light chain determination reagent for diagnosing multiple myeloma

The invention discloses a free light chain determination reagent for diagnosing multiple myeloma, and relates to the technical field of determination reagents, the free light chain determination reagent comprises a specific primer pair A and a probe A; the specific primer pair A is a primer pair composed of DNA as shown in a sequence 1 of a sequence table and DNA as shown in a sequence 2 of the sequence table; the nucleotide sequence of the probe A is shown as a sequence 3 in the sequence table, and the positive plasmid contains an NY-ESO-1 gene. According to the free light chain determination reagent for diagnosing multiple myeloma, the NY-ESO-1 gene is expressed in bone marrow or peripheral blood of many multiple myeloma patients, the NY-ESO-1 gene is not expressed in bone marrow or peripheral blood of normal people, and the positive rates of the NY-ESO-1 gene are different in bone marrow or peripheral blood of multiple myeloma patients in different ISS stages. The reagent can be applied to qualitative auxi