Measuring device and measuring method for roundness of large-size mechanical part

The invention discloses a device and a method for measuring the roundness of a large-size mechanical part, and belongs to the field of measuring devices. The device comprises a bracket and a plurality of measuring devices. And the plurality of measuring devices are arranged at the lower end of the bracket. The bracket 1 comprises two fixing devices 11, two metal connecting blocks 12 and a rubber belt 14; the side face of each fixing device 11 is fixedly connected with a corresponding metal connecting block 12, the rubber belt 14 is fixedly connected between the two metal connecting blocks 12, and a sliding groove 13 is formed in the end, away from the rubber belt 14, of each metal connecting block 12. The lower end of each metal connecting block 12 is fixedly connected with a measuring device 2, and the lower end of the rubber belt 14 is fixedly connected with a plurality of measuring devices 2. The measuring devices 2 are fixed on the two sides of the part 3 through the fixing devices 11; the device not only