Detection device and detection method for blade margin plate arc

The invention discloses a blade margin plate arc detection device and method. The detection device comprises a bottom plate, a gauge setting block, an arc sliding seat, a lower arc gauge seat and an upper arc gauge seat. A positioning structure is arranged on the bottom plate and is used for mounting a blade workpiece to be detected; the meter setting block is mounted on the bottom plate; an upper arc pair surface and a lower arc pair surface which are distributed up and down at an interval are arranged on a stand column of the gauge setting block; the upper arc pair surface and the lower arc pair surface are respectively positioned on extended arc surfaces of theoretical values of an upper arc surface to be detected and a lower arc surface to be detected of an upper margin plate of a blade workpiece to be detected; the arc-shaped sliding seat is mounted on the bottom plate, and the arc-shaped surface of the arc-shaped sliding seat and the circle center of a to-be-detected upper arc surface or a to-be-detecte