The invention provides a processing method for reducing and recycling organic waste water. The method comprises steps: (1) pre-treating waste water to obtain pre-treated out-water; (2) treating the out-water obtained from the step (1) through solid-liquid separation; (3) nano-filtering the out-water obtained from step (2); (4) treating nano-filtered concentrated water obtained from the step (3) to obtain out-water subjected concentrated water nano-filtering, returning to the step (3) for mixing the out-water subjected to concentrated water nano-filtering with the out-water subjected to solid-liquid separation, and performing nano-filtering; (5) performing first reverse osmosis treatment on out-water obtained from the step (3) through nano-filtering; (6) performing second reverse osmosis treatment on concentrated water obtained from the step (5) through first reverse osmosis treatment; and (7) evaporating and crystallizing a concentrated liquid obtained from the step (6) through second reverse osmosis treatment in order to obtain crystallized salt and evaporated concentrated water. The invention further provides a processing system of the method. Through the method and system, waste water is truly reduced and recycled.