The invention discloses lime-free B05-level autoclaved aerated concrete which is prepared from dry materials and auxiliary materials. The dry materials are prepared from the following components in percentage by weight: 40 to 70 percent of yellow river sand, 20 to 40 percent of common cement, 1 to 7 percent of special cement, 1 to 10 percent of desulphurization gypsum and the balance of wastes, wherein the wastes are leftovers produced by cutting in the process of producing autoclaved aerated concrete building blocks; the auxiliary materials comprise hydrogen peroxide, potassium hypermanganate, a foam stabilizer, a water reducing agent and polypropylene fibers; the hydrogen peroxide metered in H2O2 accounts for 0.30 to 0.39 percent of the weight of the dry materials; the potassium hypermanganate accounts for 0.015 to 0.02 percent of the weight of the dry materials; the foam stabilizer accounts for 0.02 to 0.04 percent of the weight of the dry materials; the water reducing agent accounts for 0.05 to 0.15 percent of the weight of the dry materials. The product adopts low-cost yellow river sand instead of lime, and the relatively cheap hydrogen peroxide is used as a foaming agent, so that the performance of the product meets the requirements of the national standard.