Abstract: An improved Web firewall attack capture technology is proposed based on link vulnerability detection algorithm.Web firewall parsing model with multilevel processing scheme is designed.The chain link selection criterion is taken for attack phase reorganization.The attack information queuing analysis mechanism is introduced.HFM decomposition is taken for the link vulnerability data,the attack packet signal model is constructed.Slow link vulnerability layer fading is analyzed.The aliasing spectrum ambiguity function is used for spectrum analysis,nonlinear dynamic approximate optimal model is obtained,link layer vulnerability detection is obtained,accurate capture of Web firewall to attack packets is completed.The simulation experiments show that the algorithm can accurately capture the attack data,contour map has higher resolution,Web firewall output data has high SNR,it has good performance in network security detection.