The invention relates to an oil-water separation device. The oil-water separation device is provided with an oil-water separation groove, wherein the oil-water separation groove is provided with an oil-water mixed solution inlet, a blow-down outlet and a dirty oil drainage outlet; at least three oil separation clapboards which are arranged at intervals are arranged in the oil-water separation groove, the oil-water separation groove is separated into a plurality of compartments by the oil separation clapboards, gaps are formed between the bottom edges of the oil separation clapboards and the bottom of the oil-water separation groove to be mutually communicated with the lower parts of the various compartments, the bottom of the oil-water separation groove is slantwise arranged to enable an oil-water mixed solution to enter the oil-water separation groove from the oil-water mixed solution inlet so as to pass through the gaps, and forms a dirty oil layer and a sewage layer after being separated by the multi-layers of the various compartments, dirty oil in the dirty oil layer can be drained out of the oil-water separation groove through the dirty oil drainage outlet, and sewage in the sewage layer can be drained out of the oil-water separation groove through the blow-down outlet. The oil-water separation device disclosed by the invention has the advantages of meeting the requirement of being used under the working condition of ship swaying, saving a space in a ship, and being compact in structure, reliable in working, convenient to check, and convenient to maintain.