Light high-strength anti-crack cement-based building heat insulating material and preparation method thereof

The invention discloses a light high-strength anti-crack cement-based building heat insulating material and a preparation method thereof. The material comprises, by weight, 34-59 parts of cement, 24-58 parts of coal ash, 6-17 parts of silicon ash or nano-silicon dioxide, 0.24-0.57 part of water reducing agents, 0.25-0.4 part of foaming agents and 0.03-0.04 part of silane coupling agents. Syntheticfibers added in the water adding and blending process of the material. The preparation method of the material includes the steps: 1) mixing and stirring the cement, the coal ash, the silicon ash or nano-silicon dioxide, the water reducing agents and water to obtain slurry I; 2) dispersing the synthetic fibers into the slurry I to uniformly stirring mixture to obtain slurry II; 3) mixing and stirring the foaming agents, the silane coupling agents and water to prepare foams, adding the foams into the slurry II, uniformly stirring the mixture to obtain foam concrete slurry III, and performing injection molding, demoldin