This invention discloses a method for predicting the service life of a retired power battery. The service life of a retired power battery may be predicted by its power battery life attenuation curve. The power battery life attenuation curve is obtained by establishing a power battery life model and a charge and discharge characteristic curve of the power battery by utilizing the temperature T, the discharge rate C and the discharge depth DOD in the charging and discharging process of the power battery. This invention establishes a three-dimensional relation graph with a cycle life with respect to the capacity loss rate and the functional relationship ω=ƒ(T,C) by using the power battery life attenuation curve. The three-dimensional relation graph is applied to the same type of battery. And the attenuation of the battery in the full life cycle may be predicted.