An encoding method and apparatus is described. In an encoding method, when a first target sub-block in a target block is obtained, a hash operation is first performed on the first target sub-block. Then, a first hash table is queried for a corresponding hash value according to an operation result, and a corresponding location in a reference block is found according to the hash value obtained by means of query, that is, first reference data is found. The first piece of target data in the first target sub-block is matched with the first reference data, and second target data in the target block is matched with second reference data in the reference block. In this way, an approximate location is predetermined, so that a range in which matching needs to be performed is narrowed, a data compression time is reduced, and data compression efficiency is improved.