The invention discloses a preparation method of a Kevlar fiber hollow sphere, which is characterized by comprising the following steps: gumming a sphere by taking the sphere made of a polystyrene foaming material as a carrier, feeding the sphere into an environment, in which fiber strips made of Kevlar fibers and processed by a vacuum electrostatic field suspend, so that the high-pressure hovered Kevlar fibers and the sphere are synthesized under a high charge state, so as to obtain a fiber solid sphere; feeding the fiber solid sphere into a high temperature environment being 100 DEG C or hotter, so that the polystyrene foaming material in the fiber solid sphere is melted; finally, heating up to 150 DEG C for hot air blow heating, so that glue is completely cured to form a vacuum tight hollow fiber sphere. The preparation method has the advantages that the structure of the product is simple, the preparation is simple and convenient, and the production efficiency is high; in addition, the prepared product has good stability and physical property.