The invention relates to a method for treating high-fat wastewater of food industries. The method comprises the following steps: (A) after wastewater flows through multiple grids, pumping the wastewater into a bending-flow type hydrolysis reactor for treating, introducing the wastewater into an anaerobic aeration tank, and carrying out anaerobic treatment; (B) introducing the wastewater into a coagulating tank for coagulation, regulating the pH to 7.5-8.5, firstly carrying out solid-liquid separation, and carrying out floating separation; (C) carrying out oxidation treatment on the wastewater by virtue of ultrasonic compound supercritical water, filtering by virtue of activated carbon, and carrying out sedimentation; and (D) sequentially carrying out security filtering, micro-filtration membrane filtering, ultrafiltration membrane filtering and reverse osmosis membrane filtering, so as to obtain discharged water meeting the environmental protection standards. Compared with the prior art, the method has the advantages that the organic matters in the high-fat wastewater of the food industries can be effectively degraded, the acidity of the wastewater is reduced, suspended solids such as COD and grease, metal oxides, colloids, bacteria and the like can be effectively removed, the wastewater can be economic, efficient and bulk treatment of the wastewater can be realized, the operation is simple, the operation cost is low, the occupied area is reduced, and the treating effect is remarkable.