An energy-saving environment-friendly exterior wall hanging plate comprises 20-30 parts by weight of cement, 40-50 parts by weight of silica fume, 5-12 parts by weight of fly ash, 5-10 parts by weight of wood fibers, 0 to 1.5 parts by weight of hydroxypropyl methylcellulose, 5-20 parts by weight of building material waste and 30-40 parts by weight of water, wherein the building material waste is waste materials generated during production process of building materials and building and construction process and waste materials removed from buildings, and the building material waste is particles with the particle size greater than 70 mesh. A larger proportion of building material waste is used for replacement of the cement, the silica fume, the fly ash, the hydroxypropyl methylcellulose and other raw materials, and while significant reduction in production cost, same product performance can be maintained.