The invention relates to a high-accuracy roundness detection method based on the combination of reverse and multi-sensor methods. The method comprises the following steps of: making two discs with the same shape error, taking one disc as a reference disc and rotating the other disc for 180 degrees coaxially, fixing the two discs mutually; arranging the fixed two discs on a testing platform of a roundness tester coaxially and enabling the circle centers of the two discs to be coincident with the rotation center of the roundness tester; and putting a detected workpiece on the discs and also enabling the circle center of the detected workpiece to be coincident with the rotation center of the roundness tester. In measurement, an inclined angle formed by two sensors connected with the discs is180 degrees, workpiece shape errors in two paths of combined signals output by the sensors are same both in size and direction, and the rotation errors of a spindle are same in size and opposite in direction, therefore the rotation errors of the spindle can be separated out, and then the shape errors of the detected workpiece can be obtained, and the roundness of the detected workpiece can be obtained finally. By the method disclosed by the invention, the roundness of a workpiece can be measured accurately.