The invention relates to a high-strength lightweight 
forsterite fireproof material and a preparation method therefor. The scheme is as follows: the preparation method comprises the steps: firstly, uniformly mixing a siliceous 
raw material, a 
magnesium salt, a zinciferous 
raw material, 
iron powder and 
boric acid, carrying out forming, carrying out heat treatment in a 
reducing atmosphere, and carrying out 
grinding, thereby obtaining a material A; then, mixing the material A, a surfactant, a thickener, an additive and water, and carrying out ball-milling, thereby obtaining 
slurry; then, uniformly mixing a siliceous 
raw material, fine magnesia 
powder, a zinciferous raw material, municipal 
sludge and a surfactant, carrying out forming, carrying out heat treatment in a 
reducing atmosphere, carrying out heat treatment in a 
neutral atmosphere, and carrying out 
grinding, so as to obtain a material B and a material C; and finally, uniformly mixing magnesia granules, fine magnesia 
powder, a siliceous raw material, the material B, the material C, a zinciferous raw material and the 
slurry, carrying out forming, and carrying out heat treatment, thereby preparing the high-strength lightweight 
forsterite fireproof material. According to the high-strength lightweight 
forsterite fireproof material and the preparation method therefor, the source of the raw materials is wide, and the production cost is low; and the prepared product is excellent in high-
temperature resistance, high in strength and small in high-
temperature coefficient of 
thermal conductivity and can be used in a long term in high-temperature environments in contact with 
reducing atmosphere, alkaline dust and the like.