The invention relates to the technical field of transformer oil and in particular relates to a metal-organic framework material as well as a preparation method and application thereof. The invention provides the preparation method of the metal-organic framework material; the preparation method comprises the following steps: mixing an organic ligand, inorganic salt, ethanol water and dimethylformamide or diethylamide and reacting to obtain a powdery metal-organic framework; then granulating and molding to obtain a granular metal-organic framework. According to the method provided by the invention, the metal-organic framework material is obtained through granulation and molding, so that the metal-organic framework material has a stable shape and has large specific surface area, pore capacityand pore diameter. Compared with other adsorbents with the same use amount, the metal-organic framework material provided by the invention has a high adsorption amount on degraded transformer oil andhas high-efficiency and excellent adsorption performance, so that the dielectric loss reduction rate of the degraded transformer oil can reach 98 percent or more and the volume resistivity rising rate can reach 1919.42 percent at maximum; both the interface tension of the transformer oil and the color of an oil sample are improved.