A data processing method includes the steps of: initializing a syndrome vector to be an (n−1)th symbol; finding a corresponding mask based on the syndrome vector, wherein the mask is zero when the (n−1)th symbol is zero; correcting a known constant, which is zero when the syndrome vector is zero, based on the mask; inputting the syndrome vector to a log look-up table to correspondingly find log data; performing a modulo addition operation corresponding to log maximum data to find a log sum based on the log data and a log known constant; and inputting the log sum to an anti-log look-up table to correspondingly find operational data.