The invention discloses an improved concentric-square-shaped machine tool protection cover. The improved concentric-square-shaped machine tool protection cover comprises a plurality of protection cover bodies being internally and externally in cup joint. A plurality of connecting mechanisms are arranged between the two adjacent protection cover bodies. Each connecting mechanism comprises a first positioning plate fixed to the protection cover body on the outer side, wherein a first sliding rail is fixed to the first positioning plate and is in sliding cup joint with a sliding block; and a second positioning plate is arranged on the protection cover body on the inner side, a second sliding rail is fixed to the second positioning plate, the second sliding rail is in sliding cup joint in the sliding block, and the first sliding rail is perpendicular to the second sliding rail. The improved concentric-square-shaped machine tool protection cover can overcome the defects in the prior art, the improved concentric-square-shaped machine tool protection cover can move in the two directions at the same time through one mechanism, on one hand, the movement distance of a machine tool spindle is reduced, the two branch movements can become a combined movement, on the other hand, unnecessary time is shortened, and the machining efficiency is improved.