Abstract: The problem of network security has attracted the attention of the entire world, because network security problems annually give a lot of network users resulting in loss of life and economic. This study improves the PDRR safety monitoring model and proposes a network security monitoring system model of DOM security data tag tree, finally its model is studied experimentally. Through the study found, DOM security data label tree network monitoring system can ensure the smooth transmission of data which can effectively block the malicious attacks and compared to the previous PDRR, it has good clustering and dividing partition function, improving the efficiency of network security protection. Through the network data transmission security testing, we found that the most obvious effect is the intercept on the IP fraud, before the improved is 18 times and after the improved drops to 1 which verify the effectiveness of network security monitoring system, to provide a theoretical reference for the study of network security monitoring scheme.