Loading spectrum statistic acquired from proving ground has great effect on the component fatigue life prediction.a fatigue damage and life prediction method based on the acceleration signal was put forward,this method is applied to engine mount bolt whose loading spectrum can’t be directly acquired in working condition. First,by macrofracture observation and mechanical model analysis,the relationship between the main stress load and acceleration load of different condition was defined.Then according to the S-N curve of engine mount bolt,and applying the acceleration signal in different working condition,bending moment and tensile stress in time series was calculated. The engine mount bolt fatigue damage was figured out based on those time series. Finally,by compearing with the fatigue life of two measured roads,the equivalent relationship between the two roads is established.