The invention relates to a nano-sized composite silica brick and a production method thereof. The invention is characterized in that: raw materials and binder of the silica brick are as follows: silica granules and fine powders, waste silica brick granules, calcium carbonate nanoparticles, iron oxide nanoparticles, silicon dioxide nanoparticles, fluorite powders, lime and sulfite pulp wastes. The production method is based on the existing production process of the silica brick, and introduces compound nanopowders in optimal proportions in the production process of the silica brick after high-efficiency dispersion, to produce nano-sized composite silica bricks. With the addition of nanopowders, the performance of silica brick is significantly improved, and manifested as follows: 1) the particle size fraction is more reasonable, the accumulation is compact and the texture is uniform; 2) the slurry has good plasticity and moldability and the production efficiency is improved; 3) the burning temperature is decreased to 20 DEG C, thus realizing energy conservation and discharge reduction; 4) the tridymite is superior in crystallization conversion and has low content of quartz residues; 5) the number of closed pores is increased, the number of opened pores are reduced, the porosity is reduced, and the strength and refractoriness under load are increased; and 6) the final product has good appearance, smooth end surface and good bonding property, and the rate of qualified products is increased.