Rain-flow counting method is adopted to cycles from the fatigue stress spectra of a truss nodegain different stress amplitudes and their corresponding stress The W eibull probability distribution fitting is applied to the above resuhs．Based on Miner linear cumulative damage theory of fatigue，the datum of rain—flow counting results and Weibull probability distribution fitting results are used to estimate the fatigue life of the truss node．The experimental results show that the combination of the rain．flow counting method with the probability distribution fitting technique makes the estimation of the fatigue life more authentic．