The invention provides a chemoluminescence immunoassay measuring kit and a preparation method thereof for quantificationally detect triiodothyronine (T3) magnetic particles. The kit mainly comprises a triiodothyronine serial calibration sample, magnetic particle solution coated by an anti-fluorescein isothiocyanate (FITC) monoclonal antibody, a T3 antigen marked by biotin, T3 monoclonal antibody marked by FITC, streptavidin marked by alkaline phosphatase, chemoluminescence substrate solution and 20-time concentrated washing solution. The invention adopts a competitive-method reaction mode, effectively utilizes the chemoluminescence technology combined with magnetic particles and biotin-avidin immunity magnifying technology principle to quantificationally detect the content of T3 in blood serum and blood plasma samples of human bodies and ensure the sensitivity of the detection. The kit is simple, convenient, fast, sensitive and stable to use, and provides a very valuable detection method for clinic diagnosis and scientific research works.