The embodiment of the invention discloses a decoding method and a device. The decoding method comprises the following steps: a maximum likelihood path is obtained according to the received decoding data and backdates along the maximum likelihood path to output a maximum likelihood sequence. The maximum likelihood sequence is checked to judge whether the maximum likelihood sequence passes the inspection. If passing, the maximum likelihood sequence is output as a decoding output sequence; or else, the maximum likelihood sequence chooses a backtracking node along the maximum likelihood path and backtracks along the backtracking node, and then a trail sequence is output and checked. The trail sequence passing the inspection is output as the decoding output sequence, or the maximum likelihood sequence is output as the decoding output sequence when all trail sequences do not pass the check. The embodiment of the invention respectively inspects each group of decoding sequence. A group of sequence which passes the inspection of check codes is chosen as the decoding output sequence of the decoding data so as to reduce the block error rate of the coding and enhance the performance of a communication system.