The civil aircraft full-scale fatigue test will need too long period and high cost under conventional technology,which affects the airworthiness certification and service use.Carrying out the load spectrum simplification research can effectively accelerate the fatigue test.The equivalent damage conversion method taking the threshold value of damage ratio as the conversion basis was established to simplify the load spectrum,which combining detail fatigue rating method with linear damage accumulation theory.Two kinds of bolted and riveted test pieces were selected for test verification.The original spectrum was reduced to five level spectrum and three level spectrum respectively.The number of cycles was reduced by about 98% and the fatigue life met the engineering requirements after conversion.The correctness and effectiveness of these acceleration methods are proved.