A low complexity method was proposed for the blind recognition of BCH codes under error conditions. The existing recognition methods most come from the generic methods of linear block codes, which can't be applied when the code length is long and the bit error rate is high. This method is based on that the BCH codes come from the sub-space of Hamming codes, so the parity check matrix of the hamming codes can be used to check the BCH codes. The method contains recovering the code length, synchronization and generator polynomial. The simulations show that the algorithm runs successfully for a BCH code with length 1023, when the bit error rate is 0.5%.