The invention discloses a device for automatically adjusting blade overlapping of a circle shear, and relates to the technical field of circle shears, the device comprises a supporting seat, a first disc and a second disc, a device main body is mounted above the supporting seat, a transmission shaft is mounted on the left side of the device main body through a bearing seat, and the second disc is arranged on the left side of the first disc; a first bearing and a second bearing are arranged on the upper side and the lower side in the arc-shaped groove correspondingly, and a first connecting column is installed between the first bearing on the first disc and the first bearing on the second disc. The device for automatically adjusting blade overlapping of the circle shear is provided with the first disc and the second disc, the fine adjustment motor drives the first disc and the second disc to rotate, then the first movable strip, the second movable strip and the blade device are driven to move, accurate adjustment of the overlapping amount of the blade device is achieved, and compared with traditional manual adjustment, the efficiency is improved. The adjusting efficiency is greatly improved, production stagnation caused by too long adjusting time is reduced, and the smoothness of the production process is improved.