The invention provides a preparation method for an electroluminescent sheet dielectric layer. The preparation method for the electroluminescent sheet dielectric layer comprises steps of A preparing aFeNi3 alloy submicron ball, B coating the FeNi3 alloy submicron ball with an SiO2 dielectric shell layer to form a core shell structure, and C, performing spinning coating to prepare the dielectric layer. The organization structure of the electroluminescent sheet dielectric layer and the preparation method for the electroluminescent sheet dielectric layer have advantages of a simple ratio and simple preparation processes, the obtained dielectric layer is good in dielectricity and micro-nano particles have no agglomeration phenomenon and light emission is uniform.