Disclosed are a decoding method and a decoding device. In the method, a received sequence and a generator matrix are processed to obtain a hard-decision information sequence and a hard-decision codeword; an error pattern is determined according to the hard-decision information sequence and the hard-decision codeword; then, the error pattern is post-processed and an optimal decoding sequence is output as a decoding result, wherein the optimal decoding sequence is a decoding sequence with a minimized Euclidean distance. According to the present disclosure, the complexity of the algorithm is reduced while the effective decoding performance can be ensured.