The utility model provides a fatigue test system for traffic load application. The device comprises a first stand column, a second stand column, a first cross beam, an actuator, a loading shaft, a wheel set, a hydraulic oil cylinder system, a detection element and a data processing unit, the two ends of the first beam are perpendicularly and fixedly connected with the first stand column and the second stand column. The sliding rail is arranged on the first cross beam; the horizontal adjusting piece pushes the actuator to horizontally move along the sliding rail; the actuator is fixedly connected with one end of the loading shaft; the other end of the loading shaft is fixedly connected with the wheel set; the wheel sets make contact with a pavement structure. The detection elements are respectively arranged in the pavement structure and the roadbed structure; the test system disclosed by the utility model can well simulate the dynamic load of a road vehicle acting on the road surface and the roadbed structure in the driving process, and meets the simulation and detection of the fatigue damage of the roadbed and the road surface under the action of the traffic load.