A device for eliminating a gap between a stator core and a support rib of a large generator relates to the technical field of generators and comprises two symmetrically arranged adjusting frames, Theadjusting frame comprises a vertical bar, an upper cross bar and a wedge, wherein an upper cross bar is arranged on the upper side of the vertical bar, a wedge is arranged on the lower side of the vertical bar, two wedge blocks of the adjusting frame are respectively inserted between a support bar and a stator core, a through hole is arranged on the upper cross bar, bolts are arranged in the two opposite through holes, and nuts are fastened on the bolts. The device can eliminate the gap between the stator support bar and the iron core accurately and effectively, and has certain data measurement function. In unit maintenance, relaxed noise reduction treatment can be quickly performed to ensure the safety and reliability of the unit again.