The invention relates to a convolutional code decode method, which comprises: based on Viterbi algorithm, obtaining globe optimized path, obtaining decode data; checking the decode data; if the code is right, outing code, ending; or else, searching for other globe optimized paths and decode data, as based on known globe optimized paths, separating from selected path at each time of each globe optimized path, searching for local sub-optimized path, obtaining the difference between relative globe optimized path and optimized path, obtaining one globe optimized path, obtaining relative decode data; checking the decode data, if the check is wrong, searching for other globe optimized paths.