Threedimensional finite element models of neatly fitted rivet lapjoint containing multiple site damage (MSD) cracks are developed and the concept of equivalent stress intensity factor (SIF) is introduced based on the calculation of different sides of the crack tip. On the basis of Paris formula, and combined with the improved loadcycles cumulate method, a prediction method for MSD crack growth under constant amplitude cyclic loading is established, and plastic zone linkup criterion and coherence treatment in MSD evolution are integrated. The results of calculation and experiment show that the prediction results are in good agreement with experimental results, the errors of three damage modes are within 7 percent; the analysis for lapjoint cannot be simplified into plate model, the crack growth life of MSD structure is highly conducted by the mode of damage, the more cracks exist, the faster the cracks grow.