A data compression method includes providing one or more data block sets, where each data block set includes a plurality of data blocks with a same fingerprint; providing one or more compression groups based on a similarity degree between a plurality of data blocks included in each data block set, where one compression group includes a plurality of similar data blocks, the plurality of similar data blocks are a subset of data blocks included in the one or more data block sets, and a similarity degree between the plurality of similar data blocks meets a specific similarity condition; and compressing the plurality of similar data blocks included in the compression group.