Chemiluminescence immunoassay (CLIA) is currently recognized as an advanced immunodiagnostic technology in the world, with advantages of high sensitivity, strong specificity, and wide detection linear range. It has been widely used in the diagnosis of tumor markers, infectious diseases, endocrine function, and hormones. Magnetic-based chemiluminescence immunoassay is a combination of magnetic separation, chemiluminescence and immunoassay. Magnetic microspheres play the role of carrier in chemiluminescence immunoassay, which can be conjugated with antibodies, antigens, or streptavidin.