A method for data management in a flash memory medium is provided in the present invention, The method comprises the following steps: dividing a plurality of blocks of the flash memory medium into two or more sections; generating a section-address-mapping table by scanning logic addresses in the blocks in each section; storing the section-address-mapping table into a backup block in each section; and performing an operation of writing/reading by reading the section-address-mapping table, storing the section-address-mapping table to a RAM, and performing a conversion between a physical address and a logic address based on the section-address-mapping table stored in the RAM. Since the section-address-mapping tables are stored in the backup block in respective sections, when an operation of writing/reading is performed and it is necessary to switch to a section-address-mapping table for a next section, data stored in the next section can be read out based on the section-address-mapping table stored in the backup block in the next section, without needing to scan each block in the next section for generating a new section-address-mapping table dynamically. Therefore, the method of the present invention can save the time for operation and thus achieve effective management on data in the flash memory medium.