The invention belongs to the technical field of waste residue recycling and particularly relates to the technical field of preparation of building blocks by recycling of polycrystalline silicon wasteresidues. The method comprises the following steps: putting wastes produced in the production process of the polycrystalline silicon into a leaching pool, after hydrolysis, alkali liquid spraying andabsorption and neutralization, primarily forming waste residues in the leaching pool, adding tap water according to the mass ratio of leached waste residues to water being (1-3):1, and stirring to obtain slurry; and adding the following components: 20-26 parts of phosphorus slag residues, 17-19 parts of organic silicon waste residue slurry, 14-16 parts of natural siderite, 4-11 parts of cement, 5-7 parts of gypsum into feed liquid, carrying out filtering press to obtain insoluble residues, storing, rolling uniformly by using wheels, then carrying out compression molding, and carrying out autoclaved curing to prepare an unfired type building block. The preparation of the building blocks consumes a large amount of polycrystalline silicon waste residues and tailing sand, the utilization rateof the waste residues is 86% or above, the wastes are changed into valuables, and chemical pollution sources are changed into usable resources, so that the energy-saving and environment-friendly benefits are obvious.