A system for composting-free disposal of organic waste and method thereof included a heating apparatus, a pretreatment apparatus, and a decomposition apparatus. The heating apparatus heats the pretreatment apparatus and the decomposition apparatus. The organic waste is separated into a slurry and a surface oil-water mixed liquid by the pretreatment apparatus. Microbial enzymes and raw material are added into the slurry to become a mixture. The mixture is then decomposed and sterilized by the decomposition apparatus to become a composting-free organic fertilizer product. All these procedures can be carried out within 3 to 24 hours. The system and the method thereof provides an efficiently fast, space-saving way to deal with organic waste and achieve environmental protection and sanitation.