The invention provides a method for manufacturing a compound heat-preserving board. The method for manufacturing the compound heat-preserving board is characterized by comprising the steps: preparing an organic fiber raw material, preparing an inorganic porous raw material, preparing a cementing agent, preparing auxiliary materials, preparing additive raw materials, mixing the raw materials, cementing, and pressing the mixture. The compound heat-preserving board is manufactured by cementing the organic fiber raw material, the inorganic porous raw material and auxiliary materials by using an inorganic cementing agent and pressing the mixture, so that the manufactured heat-preserving board is flame-retardant, low in volume weight, good in heat-insulating and heat-preserving performance, wide in material source and low in price; wastes are utilized, so the an environment-protecting effect is achieved; and the manufactured heat-preserving board is suitable for being used as a heat-preserving and heat-insulating material for a wall surface of a building.