A method for estimating battery life based on an alternating-current impedance spectrum includes the steps that first, the battery impedance in the ith preset period is acquired through an alternating-current impedance spectrum method; second, whether the impedance of a battery is equal to preset impedance or not is judged, and if the impedance of the battery is larger or smaller than the preset impedance and smaller than theoretical maximum impedance, a correction parameter corresponding to the internal resistance of the battery is acquired from a corresponding relation chart of the preset internal resistance and correction parameters, and the theoretical service life of the battery is corrected and serves as new theoretical service life; third, whether the new theoretical service life is shorter than or equal to the actual service life of the ith preset period or not is judged, and if the new theoretical service life is shorter than or equal to the actual service life of the ith preset period, service life testing is ended; fourth, if the updated theoretical service life is longer than the ith preset period, when a next preset period of the battery starts, the i is increased by one, the i+1 serves as an updated i, and when the new theoretical service life is longer than the new ith preset period, the steps from the first step to the third step are repeatedly executed. The service life detection method is applicable to detection of service life of batteries in various types and various charging and discharging modes.