The invention belongs to the technical field of high polymer materials, and particularly discloses a modified melamine hard foam material and a preparation method thereof, and the modified melamine hard foam material is composed of the following raw material in parts by weight: 30-60 parts of melamine, 15-40 parts of paraformaldehyde, 10-35 parts of water, 5-20 parts of isobutanol, 3-10 parts of benzoxazine and 5-15 parts of polyvinyl butyral. The prepared melamine hard foam material has the characteristics of being low in powder falling rate, high in closed porosity, high in strength, good intoughness and high in bonding strength between post-processing treatment and a matrix.