The invention discloses an insulated rubber material and a preparation method thereof. The insulated rubber material is prepared from the following raw materials in parts by weight: 100 parts of butyl rubber, 30-40 parts of nitrile butadiene rubber, 30-40 parts of cis-1,4-polybutadiene rubber, 4-6 parts of sulfur, 2-3 parts of zinc oxide, 2-4 parts of stearic acid, 1-2 parts of accelerator PZ, 0.5-1 part of accelerator DM, 0.5-1 part of accelerator TBT, 0.5-1.5 parts of anti-aging agent 445, 0.5-1.5 parts of anti-aging agent ODA, 2-6 parts of thiodipropionic acid, 1-4 parts of SN, 4-8 parts of liquid coumarone resin, 30-40 parts of carbon fibers and 45-65 parts of white carbon black. The insulated rubber material and the preparation method have the beneficial effects that the wear resistance, oil resistance and deformation and damage resistance are improved; the physical properties of the material are improved through improvement of the process and proportioning of the material; the insulating property and aging resistance of the material are further improved and the service life of the material is further prolonged.