The invention provides a magnetorheological elastomer which is prepared from the following raw materials: a rubber matrix, a magnetic particle, a carbon nano tube and a plasticizer. The carbon nano tube is reinforced in the magnetorheological elastomer, the mechanical strength, a heat conduction characteristic and a magneto-induced modulus characteristic of the magnetorheological elastomer can be increased due to a unique microstructure and high heat conductivity of the carbon nano tube, and an application of the magnetorheological elastomer in the field of transformer damping is expanded. At the same time, a technology of the elastomer is simple; a material finished product is easy to form; and industrialization and commoditization are easy.