The invention discloses a pollution-free silicate bacterium fertilizer, which is composed of the following raw materials in parts by weight: 4 to 7 parts of tobacco powder, 3 to 5 parts of potassium sulfate, 40 to 60 parts of straw, 5 to 8 parts of potassium dihydrogen phosphate, 2 to 3 parts of trichoderma sp, 3 to 5 parts of copper sulfate, 4 to 6 parts of perlite, 5 to 6 parts of oyster shell, 6 to 8 parts of attapulgite, 1 to 2 parts of ammonium molybdate, 120 to 140 parts of chicken manure, 5 to 8 parts of wild buckwheat, 2 to 4 parts of silicate bacterium inoculant, 4 to 7 parts of wollastonite, and 5 to 7 parts of auxiliary agent. The fertilizer is mainly composed of chicken manure and straw, other additives such as ammonium dihydrogen phosphate, copper sulfate, and the like are added, thus the provided fertilizer can guarantee that crops have enough nutrients in each stage of growth, moreover, the agricultural wastes are fermented in multiple steps and converted into valuable resources, no pollution or residue is generated during the fermentation process, and thus the provided preparation method has a very good application prospect.