Fatigue life prediction of sheet specimens of 2024‐T3 aluminium alloy subjected to cyclic bending and a corrosive environment is achieved by Monte Carlo simulation in which three steps are carried out. Firstly, the crack distribution function and crack size distribution function are obtained by experiments. Secondly, the stress distribution and the interaction of cracks as well as the crack propagation rate is found by dislocation functions. Thirdly, a coalescence criterion is proposed to predict the formation of cross surface cracks. The predicted results agree well with experimental results.