The utility model discloses a kind of automatic centering adjusting frame, it includes clamping unit and adjusting unit;Clamping seat in clamping unit is equipped with clamping through-hole, at least three clamping arms are equidistantly distributed and set in clamping through-hole inside, and through elastic driving element, clamping arm is driven to swing, and the clamping of multiple clamping arms is gathered.In clamping circular lens, clamping force is evenly applied from multiple directions, realize quick and accurate clamping, reduce the damage risk of circular lens in clamping process, improve clamping efficiency simultaneously.Adjusting unit cooperates by setting three pushers, can realize the lifting adjustment of circular lens, inclination angle adjustment, and then realize the flexible adjustment of circular lens posture, meet the posture requirement of circular lens in optical experiment.