The invention claims a CVA-based tail-biting convolutional code channel decoding method, which relates to the field of mobile communication technology. In order to reduce the decoding complexity and increase the decoding efficiency, the present invention proposes a decoding algorithm based on the Circular Viterbi Algorithm (CVA). The decoding start position of the highest reliability is determinedbased on the likelihood ratio information of a received information sequence. The Viterbi decoding is modified from the start position, by adding a comparison and selection process, impossible statepositions are deleted, and after several iterations of search, less surviving states converge in surviving paths, the state of the largest measurement value is selected as the start position of the final decoding, and a decoding result is estimated according to its corresponding surviving path. The algorithm has a faster convergence speed, the decoding efficiency is further improved, and the decoding delay is reduced.