A coupled torsion beam axle for vehicles may include a torsion beam disposed in a vehicle width direction and trailing arms disposed at both ends of the torsion beam in a length direction of a vehicle body, wherein the torsion beam has an opened cross section formed in a reverse “U” shape by press-forming one sheet member machined so that lengths of right and left sides are different from each other on the basis of a center, and cross section widths which are different from each other along vehicle width directions of both sides on the basis of the center between the trailing arms of both sides, and front and rear surfaces formed in a wave shape along the vehicle width directions of both sides on the basis of the center.