The invention provides an ethylene glycol-based magnetic fluid composite film and a preparation method thereof, relating to the technical field of magnetic composite materials. The ethylene glycol-based magnetic fluid composite film is mainly prepared from the following components in parts by weight: 90-110 parts of ethylene glycol-based magnetic fluid, 15-25 parts of polyvinyl alcohol and 70-90 parts of deionized water, wherein the ethylene glycol-based magnetic fluid is mainly prepared from nano ferroferric oxide, ethylene glycol and a dispersion stabilizer. The technical problems that the performance of the magnetic fluid composite film is limited due to the fact that a carrier fluid matrix is water-based or oil-based and the dispersion degree of magnetic nanoparticles is not obviously improved are solved; and the technical effects are achieved as follows: the magnetic particles are uniformly distributed in the composite film through mutual coordination and cooperation of the ethylene glycol-based magnetic fluid, polyvinyl alcohol and the deionized water, and the composite film is higher in saturation magnetization intensity, high in unit mass susceptibility and better in strain capacity on the basis of keeping good paramagnetic property, thereby developing better magnetic variation performance.