Improved preparation method of heatproof baking-free brick

The invention discloses an improved preparation method of a heatproof baking-free brick. The preparation method comprises the following steps: step one, grinding sintering ash of power plants into blocks with a particle size of 10 mm; step two, mixing 35 parts by weight of sintering ash blocks with a particle size of 10 mm with 25 parts by weight of coal slag powder, 25 parts by weight of common sand, 8 parts by weight of cement, 7 parts by weight of calcium oxide with a particle size of 15 mm, 5 parts by weight of calcium silicate, 1.5 parts by weight of sodium sulfate, 1 part by weight of sodium silicate, 5 parts by weight of water soluble unsaturated resin, and 2 parts by weight of silicon powder, adding the mixture into 15 parts by weight of water, mixing, and stirring to obtain a wet material; step three, pressing the wet material into moulded baking-free bricks under a pressure of 25 MPa by a baking-free brick moulding machine; step four, naturally maintaining the baking-free bricks at a room temperatur