At present, the fatigue durability verification of domestic aircraft structure usually uses the combination of the specification spectrum and typical aircraft design mission profile to compile the fatigue test load spectrum, to evaluate the whole aircraft structure, which will cost a huge cost and cycle. So the fullscale fatigue test becomes the last and most complicated part of the structural design verification of the model airframe. In order to promote the progress of the aircraft development and the airworthiness certification, it is necessary to reduce the cost and cycle of the fullscale fatigue test for the normal aircraft whose main development requirement is economy. In the fullscale fatigue test of the CA42 aircraft airworthiness certification, the fatigue test spectrum was compiled according to the FAA approved specification spectrum, and the fatigue assessment target was adjusted from the whole aircraft structure to the the main bearing structure of the aircraft body. The loading mode of the fullscale fatigue test load was simplified accordingly, forming an efficient fullscale fatigue test method of the whole aircraft. Through this method, the whole aircraft fatigue test of CA42 only took two months. And the test cost was mainly manhours, which effectively promoted the airworthiness certification work and reduced the development cost.