Ultrahigh-flame-retardant external wall thermal insulation material as well as preparation method and application thereof

The invention discloses an ultrahigh-flame-retardant external wall thermal insulation material and a preparation method and application thereof, and belongs to the field of building thermal insulation materials.The preparation method comprises the following steps that chitosan and acetic acid are added into a solvent to be mixed, and a chitosan solution is obtained; performing ultrasonic dispersion treatment on the chitosan solution and glass fibers to obtain a mixed solution; placing the mixed solution in a mold, then placing the mold on a cooling plate for oriented freezing, and then performing freeze drying treatment to obtain the ultrahigh flame-retardant external wall thermal insulation material. The prepared material is of a porous structure and has a stable oriented lamellar structure, so that the material has excellent flame retardance, heat insulation and mechanical strength. The material can be used as a building external wall thermal insulation material, and has excellent thermal insulation perform