The utility model relates to a train air spring torsional pendulum fatigue tester, and consists of a machine rack, a workbench, a movable rack, a slideway board and an electric control cabinet; wherein, the workbench is arranged in the lower part of the machine rack, the movable rack is positioned in the upper part of the machine rack, the room between the workbench and the movable rack is left for the installation of the tested the air spring. The flank of the tester workbench connects with the output device of a crank link mechanism, and the tester reciprocates by virtue of the crank link mechanism; at the same time, the tester also has a swaying mechanism, the center distance can be adjusted; the tested air spring is arranged on the output device of the crank link mechanism and on the swaying mechanism with adjustable center distance; and is in a state of arch pendulum under the action of the above two mechanisms. Besides, the output device of the crank link mechanism is made from a variable frequency motor, a gear speed reducer and the crank link mechanism. The workbench makes use of the crank link mechanism to bring straight reciprocating motion.