The invention discloses a preparation method of a fireproof material and belongs to the technical field of preparation of fireproof materials. The preparation method comprises: keeping heat of active carbon, a sulfuric acid solution and the like; carrying out ultrasonic oscillation to prepare modified active carbon; stirring the modified active carbon with zirconium oxychloride and the like and reacting; refrigerating and carrying out secondary standing and filtering; adding titanium dioxide, boron oxide and the like, and mixing and carrying out ball milling; pressing to obtain a blank; drying and calcining to prepare the fireproof material. The preparation method of the fireproof material has the beneficial effects of simple preparation steps, easiness in sintering raw materials and small energy consumption; an obtained product has good density and has no cracking and deformation phenomena; the product has good heat shock stability and has no bursting, cracking and desolvation phenomena in a utilization process.