The invention relates to a refining and purifying device and method used for a diisopropyl ether byproduct during production of isopropanol. According to the technical scheme, the top of an extraction tower is connected with an azeotropic tower by virtue of a buffer tank for the extraction tower, the bottom of the extraction tower is connected with a pump at the bottom of the extraction tower, and isopropanol is removed by virtue of the extraction tower; the top of the azeotropic tower is connected with a reflux tank for the azeotropic tower, and the bottom of the azeotropic tower is connected to a heavy component removal tower by virtue of a pump at the bottom of the azeotropic tower; the top of the heavy component removal tower is connected with a reflux tank for the heavy component removal tower by virtue of a condenser for the heavy component removal tower, the upper part of the heavy component removal tower is connected to a refining tower by virtue of a pipeline, and a pump is arranged at the bottom of the heavy component removal tower; the top of the refining tower is connected with a reflux tank for the refining tower by virtue of a condenser for the refining tower, and an isopropanol product is obtained at the bottom of the refining tower. The refining and purifying device and method used for the diisopropyl ether byproduct during production of isopropanol have the beneficial effects that the problems of difficult purification and poor quality of the diisopropyl ether byproduct during production of isopropyl are solved, a continuous production technology is adopted, and the defects of tedious operation and high energy consumption are overcome.