The invention discloses a wideband underwater acoustic absorption and transmission material and a preparation method thereof. The wideband underwater acoustic absorption and transmission material is prepared by adhering and compounding an acoustic absorption layer with the thickness of 2-5 mm and an acoustic transmission layer with the thickness of 10-15 mm, the acoustic transmission layer is prepared from the following components in parts by weight: 100 parts of chlorinated butyl rubber, 20-40 parts of carbon black, 5-10 parts of calcium carbonate, 5 parts of dioctyl sebacate, 5-35 parts of zinc oxide, 5-35 parts of stearic acid, 0.5-1.5 part of age resister D, 0.5-1.5 parts of accelerant TMTD (Tetramethylthiuram Disulfide) and 0.5-2.0 parts of sulfur; and the acoustic absorption layer is prepared from the following components in percentage by weight: 100 parts of chlorinated butyl rubber, 20-40 parts of carbon black, 5-10 parts of calcium carbonate, 5 parts of dioctyl sebacate, 5-35parts of zinc oxide, 5-35 parts of stearic acid, 0.5-1.5 part of age resister D, 0.5-1.5 parts of accelerant TMTD, 0.5-2.0 parts of sulfur and 0.5-2.0 parts of zinc powder or iron powder. The underwater acoustic absorption and transmission rubber material has excellent physical mechanical performance as well as and acoustic transmission and absorption characteristics and can be used for researching a special underwater acoustic frequency band.