A data protection method suitable for a plurality of physical blocks mapped to a logical block in a non-volatile memory is provided. The data protection method includes recording data update information in each of the physical blocks for identifying an update relationship of the physical blocks and re-establishing the update relationship of the physical blocks according to the data update information. The data update information is composed of a plurality of words having a circular relationship, and the number of these words is greater than the number of the physical blocks. The data update information is sequentially recorded in each of the physical blocks according to the update relationship and the circular relationship.