Network security is a major issue of the current network research workers,with the continuous development of computer technology,network attack after another.Attack signatures automatically extracting technology is an important technology of network security research.To study the characteristics of network attack data extraction algorithm as the starting point,through several sequence analysis algorithm for automatic extraction ratio,the introduction of an improved algorithm,and its application,application results show that the algorithm can effectively reduce the false alarm rate compared with other algorithms in terms of a certain application value.