A data protection method for a flash memory device. In one embodiment, the flash memory device comprises a flash memory for storing protected data. After the flash memory device is coupled to a host, a plurality of current read addresses of a plurality of read commands sent from the host to the flash memory device are recorded. The current read addresses are then compared with a plurality of predetermined read addresses. When the current read addresses are not identical to the predetermined read addresses, the flash memory device is made to enter a data protection mode. When the flash memory device is in the data protection mode, if the flash memory device receives a plurality of data access commands, the data access commands are processed according to a protection mode setting parameter to prevent the protected data from being accessed by the host.