The invention provides a method for preparing a silicate inorganic foaming heat preservation and thermal insulation material. The method comprises the following steps: 1. mixing and stirring water glass and azodicarbonamide, and laying aside for a period to obtain foaming slurry; and 2. pouring the foaming slurry into a mold, calcining the mold in a muffle furnace, and cooling to obtain the foaming material. The method provided by the invention has the beneficial effects that the prepared inorganic foaming heat preservation and thermal insulation material has the advantages of small mass, high strength, heat preservation, fire protection, no pollution, low cost and simplicity in use.