The invention relates to a construction method for an AAC block free-loading wall. The method comprises the following steps: prefabricating first blocks, second blocks and concrete blocks, wherein the first blocks and the second blocks are AAC blocks and have the same size, a cubic gap is reserved in each of the left and right sides of each first block, the two gaps are positioned in two opposite corners of each first block respectively, and the concrete blocks and the gaps have the same size; building an odd number of building bodies by using the first blocks, embedding the concrete blocks into the gaps of the first blocks while carrying out building, and building an even number of building bodies by using the second blocks; after the wall is built, immediately coating an adhesion agent, anchoring anchor bolts into the concrete blocks, fixing galvanized steel wire nets on the anchor bolt, painting polymer mortar, and carrying out leveling; marking the position of each concrete block to facilitate loading and hole-forming. The construction method has the advantages of being simple, convenient and easy in construction, simple and clear in interface blocking, low in energy and material consumption, free in wall loading, controllable in deformation and firm in structure.