A height-adjustable hinge, comprising: a first middle column (12), a second middle column (22), and two bases, wherein a first base (11) in the two bases is detachably connected to the first middle column (12); a second base (21) in the two bases is detachably connected to the second middle column (22); the first middle column (12) and the second middle column (22) are rotatably connected; the first middle column (12) comprises a first curved surface, the second middle column (22) comprises a second curved surface, and the first curved surface and the second curved surface are matched, so that the relative heights of the first base (11) and the second base (21) change along with relative rotation of the first middle column (12) and second middle column (22). The height of a door can be adjusted by means of the hinge in the rotating process of the hinge, and the height-adjustable hinges can form two sets of hinges suitable for left and right doors by means of detachable connection between the middle columns and the bases.