The invention provides a method for cycling backup, including that information of data to be backed up is acquired from data source, and information and version number of the backed-up data are acquired; the information includes basic information and auxiliary information of data; the version number is the number of data versions in which the basic information are the same and the auxiliary information are different; whether the information of the backed up data contains data information the same with the basic information and auxiliary information of data to be backed up is judged, if yes, backup is not carried out, if not, when the version number of the backed up data which the basic information are the same and the auxiliary information are different with the data to be backed up is judged to be less than preset version number, the data to be backed up and information thereof are backed up, and when the version number of the backed up data is judged to be equal to the preset version number, the backed up data the same with the basic information of the data to be backed up and information thereof are updated. The invention also provides a device for cycling backup. The method and device of the invention can improve efficiency of data backup and utilization ratio of storage space.