The invention discloses a high-strength fly ash waste brick and tile-aerated concrete block and a processing method thereof. The high-strength fly ash waste brick and tile-aerated concrete block comprises the following raw materials in parts by weight: 20-30 parts of river mud, 20-30 parts of waste bricks and tiles, 10-15 parts of fly ash, 2-4 parts of phosphogypsum, 2-3 parts of flue gas desulfurization gypsum, 10-12 parts of flue ash, 4-6 parts of cement, 3-5 parts of limestone, 1-2 parts of an additive, 1-2 parts of aluminum powder, 0.1-0.2 part of zinc stearate, 0.1-0.3 part of chlorinated poly 2- hydroxypropyl-1, 1-N-methyl ammonium, 0.02-0.04 part of benzotriazole, 0.3-0.4 part of waste engine oil, 0.3-0.5 part of a carbon nanotube, 0.2-0.4 part of starch and 0.1-.3 part of oxidized polyethlene wax. The aerated concrete block disclosed by the invention is low in drying shrinkage value, good in crack resistance and good in water resistance, and the various properties can meet the national standard requirements. Compared with that of an existing product, the strength of the high-strength fly ash waste brick and tile-aerated concrete block is obviously improved.