The present invention relates to a phase change thermal interface material and preparation method, preparation steps are: the solid resin, liquid resin, an antioxidant, and a coupling agent are put into a container, while heating with stirring until mixed, then add high thermally conductive filler, heated under vacuum conditions and mixed, and then processed into a sheet or a diluent is added after cooling and stirred uniformly, and then cooled to room temperature, to obtain the phase change thermal interface material. In the present invention, the weight of the different types of thermal interface material between performance ratio of thermally conductive material, adjustable to achieve good thermal conductivity.