Abstract: Disclosed are a preparation method and application of a 4-methyl-5-vinylthiazolyl polymerized spherical ionic liquid catalyst. The method comprises: preparing a functional ionic liquid monomer successfully by taking 4-methyl-5-vinylthiazole as the matrix, and preparing the polymerized spherical ionic liquid from the monomer. The catalyst combines the advantages of both ionic liquid and the polymer, and has the characteristics of large specific surface area, high catalytic activity, high mass transfer rate, good selectivity, high stability, easy recycling and separating, environmental friendliness, wide industrial application prospect, etc.