The invention also provides a flash storage device. In one embodiment, the flash storage device is coupled to a host, and comprises a random access memory and a controller. The random access memory stores a plurality of link tables therein, wherein each of the link tables corresponds to one of a plurality of management units of at least one flash memory, and the link tables store corresponding relationships between logical addresses and physical addresses of the corresponding management units. The controller receives an access logical address from the host, determines an access physical address corresponding to the access logical address according to the link tables stored in the random access memory, and accesses data from the flash memory according to the access physical address.