Abstract: The efficiency of CRC Code Verification Algorithm was improved by CRC Table Lookup Algorithm of integer byte. The derivation showed that the traditional CRC Table Lookup Algorithm for 16 bit or 32 bit of integer byte could be extended to less than 16 bit or 32 bit of non integer byte of arbitrary. Two kinds of CRC Table Lookup Algorithm were successfully applied to the redundant coding calculation in iLOCK Interlocking System, greatly improved the efficiency of the redundant coding calculation. So the total performance of iLOCK System was improved.