Abstract: According to the damage form and corrosion features of the bottom plate of oil tank, it is considered life is amenable to the minimum distribution of peak I. On this basis, a model of reliability calculation is established on the ground of the measured data, i.e., statie reliability modelia model of reliability predication is established on the ground of the measured data, i.e., dynamic reliability model; and a model of reliable life calculation is established on the premise of the given reliability. The calculation with examples shows that these models are feasible. This will be of high significance of theoretical guidance to the corrosion activition on oil tank.