The invention discloses a building board. The building board is composed of wood composite boards, glass fiber cotton, a round cavity foam board and resonance balls. The wood composite boards are located at the two sides of the glass fiber cotton, the glass fiber cotton is located at the two sides of the round cavity foam board, and the resonance balls are arranged in the round cavity foam board. The round cavity foam board is formed by pouring two half molds, one or more resonance balls are arranged, a board body is arranged on the outer surface of each wood composite board, through holes are uniformly arrayed in each board body, pipe bodies are arranged in the through holes and are of a conical structure, and the end, with larger diameter, of each pipe body is connected with a semi-closed film. The building board is simple in structure, low in cost and good in ventilating effect and has sound insulating and absorbing functions.