The embodiments provide a method for reading and writing and a memory device. The method includes: applying a read command to the memory device, the read command pointing to address information; reading data to be read out from a memory cell corresponding to the address information pointed to by the read command; and setting a mark of the address information pointed to by the read command as invalid if an error occurs in the data to be read out, and backing up the address information pointed to by the read command and the mark into a non-volatile memory cell according to a preset rule.