The invention relates to a high-temperature-resistant binder. The high-temperature-resistant binder comprises the following components in percentage by weight: 35-40% of a sodium silicate water solution, 50-57% of kaolin with ultralow alkali metal content and 8-10% of kyanite powder. The preparation method comprises the following steps: adding the high-modulus sodium silicate and water into a high-speed dispersing machine according to a ratio, and fully dispersing; then adding kaolin with ultralow alkali metal content, and dispersing for 10 minutes at a high speed; finally adding the kyanite powder, slowly stirring for 1 minute, discharging, and finally sealing and packaging. The high-temperature-resistant binder disclosed by the invention is non-toxic and harmless, is friendly to a human body and environment, and is high in fire resistance and high in bonding strength, the bonding strength in any one temperature interval between the normal temperature and the highest use temperature is more than 2 MPa, the defect that most binders have no bonding strength at the temperature between 650 DEG C and 1000 DEG C is overcome, bonding between different materials can be realized; compared with an existing binder, the binder is more convenient to use, and the construction efficiency is improved.