The data storage device included a flash memory, divided into a plurality of blocks with each block comprising a plurality of physical pages, and a control unit, coupling the flash memory to a host and comprising a microcontroller and a random access memory. The microcontroller maintains a plurality of logical-to-physical address mapping tables and a link table on the flash memory to record mapping information between the host and the flash memory and records a link table indicator on the flash memory to indicate a position of the link table. The link table indicates positions of the plurality of logical-to-physical address mapping tables, and each entry in the link table corresponds to one logical-to-physical address mapping table. Further, the microcontroller erases user of logical addresses corresponding to N logical-to-physical address mapping tables.