The invention discloses a sound insulating material. The sound insulating material is prepared from the following components in parts by weight: 60 to 80 parts of high damping silicone rubber, 4 to 6parts of hydroxy silicone oil, 12 to 25 parts of silica aerogel, 1 to 2 parts of dicumyl peroxide, 60 to 80 parts of PP resin, 18 to 25 parts of turpentine, 20 to 30 parts of white carbon black, 23 to38 parts of foam ceramic powder, 2 to 4 parts of barium sulfate, 0.4 to 0.9 part of sodium stearate, 0.3 to 0.5 part of active zinc oxide, 6 to 10 parts of diatomaceous earth, 3 to 7 parts of zinc borate, 5 to 8 parts of high vinyl silicone oil, 0.2 to 0.4 part of aluminate coupling agent, 3 to 5 parts of vulcanizing agent, and 1.4 to 1.9 parts of accelerator. The invention also discloses a preparation method of the sound insulating material. The sound insulating material provided by the invention has the characteristics of light weight, good mechanical performance, fire retarding, and effectively absorbing low-frequency sound waves, and has the advantages of simple preparation method, low cost and mass production.