Abstract: A fatigue test acceleration method for full scale aircraft based on system soft performance optimization is proposed considering that the fatigue test speed of ARJ21-700 full scale aircraft is to be doubled during the residual 50000 flights, and the hardware equipment cannot be systematically optimized after eight years of operation and the aircraft structure damage is continuous increasing. An accelerated implementation method of full scale aircraft fatigue test is formed by optimizing the performance of system software without changing the hardware environment. The method is validated by ARJ21-700 full scale aircraft fatigue test, and the result shows that the test speed is increased by 28.6% from 77 flights per day to 99 flights per day with the method, which meets the requirements of test acceleration.