Abstract: To solve the problem of blind recognition of concentratively inserted frame synchronization, a novel fast blind recognition algorithm of frame synchronization based on dispersion analysis is proposed. Firstly, through the analysis of correlation of synchronization words and information sequences, the conclusion that the concentratively inserted frame synchronization codes have very small correlation sidelobes is got. Then, the correlation of sequences can be described according to the discrete degree analysis theory. The frame synchronization code can be cut accurately by cyclic cutting the recognition data and calculating the relative discreteness value of each segment. Finally, the synchronization word can be identified by analyzing the relative discreteness of each subsequence. Simulation results show that the new algorithm is not constrained by the type of synchronization code and the amount of data. The new method, which has higher accurate recognition than existing algorithms, has significant potential in engineering application.