The invention discloses a preparation method of a carbon fiber low-density surface coating acoustic board for KTV. A short fiber needling body is used as a preform frame, and is hardened by resin impregnation, solidification and carbonization processes. The method comprises the following steps: I, using a carbon fiber needling body as a preform material; II, preparing resin impregnation liquid; III, performing resin impregnation; IV, performing solidification treatment; V, performing carbonization treatment; VI, performing mechanical processing; VII, performing surface coating treatment to obtain the carbon fiber low-density surface coating acoustic board for KTV. According to the preparation method, after being subjected to the surface coating hole-sealing treatment, the low-density porous carbon/carbon acoustic board which takes the carbon fiber as the frame and a resin carbon matrix as a reinforcing body has the advantages of good waterproof, fireproof, anti-aging and anti-impact properties, low energy consumption of used materials, environmental protection, no pollution to the environment even if the materials are abandoned, good sound absorption effect in the use process and the like.