The invention relates to a microorganism bacterium ball and particularly discloses a purification microorganism bacterium ball as well as a preparation method and an application thereof. The purification microorganism bacterium ball disclosed by the invention is characterized by comprising the following components: coal gangue powder, clay, rice bran, saccharomycetes, lactic acid bacteria and bacillus natto. The purification microorganism bacterium ball as well as the preparation method and application thereof disclosed by the invention have the beneficial effects that the microorganism bacterium ball is prepared from scientific combination fermentation by adopting a high-activity edible fungi technique; the catabolic enzyme prepared from the microorganism bacterium ball can enable organic matters such as ammonia nitrogen, phosphorus and the like generated in polluted water bodies or lands to be decomposed and enable harmful microorganisms to be inhibited so as to carry out continuousbeneficial bacterium reproduction, pollutant degradation, water quality or land deodorization and pollution purification, thereby enabling sludge to be reduced; secondary pollution does not occur; secondary disasters do not occur; an original ecological environment is repaired; and the self cleaning capacity is improved.