The invention provides a deodorant prepared by using organic solid waste and an application thereof. The deodorant is prepared by using solid wastes such as kitchen garbage, common household garbage, sludge, garden waste, and agricultural vegetable fiber waste, A preparation method is characterized in that household garbage, agricultural waste and sludge are fragmented and mixed according to mass ratio of 1-5: 5-10: 10-15, then activated, anhydrated, carbonized, flushed, and dried to obtain mesoporous and microporous composite structures. According to the deodorant, pore volume can reach more than 0.3cm<3>/g, aperture is 1-3nm, and specific surface area is greater than 600m<2>/g. The deodorant is used for biological treatment or exhaust gas processing for solving the offensive odor processing problem in city, using waste to process the waste, and reducing the discharge amount of atmosphere PM 2.5 substance.