A method for decoding and checking a tail-biting convolutional code is provided. The method fully utilizes structural features of the tail-biting convolutional code to re-sort Log-Likelihood Ratio (LLR) values input into a decoder, and by reconstructing a derivative generator polynomial of a convolutional code, allows the decoder to output in serial according to a normal ordering of information bits during backtracking, that is, a first bit of an information sequence is first decoded successfully. Thus, CRC checking may be activated as soon as possible, so that part of the backtracking process and the CRC checking may be performed in parallel, thereby achieving the objective of reducing a processing time delay in decoding and checking the tail-biting convolutional code.