The invention discloses a coral sand insulation noise-reduction plate and a preparation method thereof, the plate is prepared from the following raw materials: coral sand, cement, polypropylene fiber,latex and composite foaming agent; the preparation method comprises the following preparation steps: step 1, mixing coral sand, cement, polypropylene fiber, latex and composite foaming agent, stirring to obtain a stirred material; step 2, loading the stirred material into a test mold, vibrating, foaming and setting, and removing the test mold to obtain a test piece; and step 3, drying the test piece, and cooling to obtain the coral sand insulation noise-reduction plate. The obtained coral sand insulation noise-reduction plate is used for adhering to the exterior wall of a building and the interior of a house, and has the advantages of light material, high bonding strength, good insulation and noise reduction effect, and the preparation method has the advantages of simple process, easy availability of raw materials and low cost. The raw material coral sand in the coral sand insulation noise-reduction plate disclosed by the invention has a porous property, which makes the coral sand insulation noise-reduction plate with a lower heat transfer coefficient, and good insulation and noise reduction effects.