The invention relates to an azeotropic oil-water separating device, and belongs to the field of chemical instruments and equipment. The azeotropic oil-water separating device comprises a pipe body, an inlet and an outlet, and is characterized in that: the pipe body consists of an upper part and a lower part which are connected to form a whole through a flange, a longitudinal inner pipe is arranged at the inner part of the lower pipe body, an upper port of the inner pipe is connected with a connector of the flange so as to form a passageway, a lower port of the inner pipe is communicated with the outlet of the pipe body, a downwards-tilted connecting pipe is connected to one side of an outer wall of the upper pipe body, an upwards-tilted connecting pipe is connected to the same side of the outer wall of the lower pipe body, the downwards-tilted connecting pipe is connected with the upwards-tilted connecting pipe through a connecting pipe parallel to the pipe body so as to form an another passageway, a port of the connecting pipe of the lower pipe body connected with the pipe body is arranged above the outlet of the inner pipe, and the outlet at the bottom of the pipe body is provided with a valve. The azeotropic oil-water separating device can be made of glass, steel, alloy, plastic, glass steel and the like according to different reaction media; and when the azeotropic oil-water separating device is applied to the azeotropic dehydration during the production in fields of pharmaceuticals, chemicals, petroleum and the like, water separating efficiency can be increased by over 50%.