The invention relates to a water body purifying microorganism, and particularly discloses a paenibacillus YE-1 and its application. The paenibacillus YE-1 is preserved at China General Microbiological Culture Collection Center, the preservation date is August 4, 2016 and the preservation number is CGMCC No. 12814. The paenibacillus YE-1 can be used for effectively absorbing degrading organic matters in black and odorous waste in a biological oxidation reactor, and purifying water quality. Furthermore, since a distributed photovoltaic system supplies power energy to an aeration device of the biological oxidation reactor, the technical flow needs not additional power energy, the operation cost is low, and the treatment is effective and stable.