Detection reagent for detecting 25-hydroxy vitamin D, as well as preparation method and application of detection reagent

The invention provides a detection reagent for detecting hydroxy vitamin D, a preparation method of the detection reagent and application of the detection reagent to immunological detection of 25-hydroxy vitamin D. The detection reagent comprises a conjugate substance and a magnetic sphere, wherein the conjugate substance is formed by 25-hydroxy vitamin D antigen derivatives and protein carriers; the magnetic sphere is coated with the conjugate substance. By modifying the 25-hydroxy vitamin D antigen derivatives, the stability of the produced reagent is obviously improved, and the specificity and accuracy in the detection of the 25-hydroxy vitamin D are also improved. The invention further provides a kit for detecting 25-hydroxy vitamin D; the kit comprises the detection reagent, and the kit is good in stability, high in accuracy and high in universality.