The determination of network equipment weaknesses and the discovery of intrusion intention is one of the difficulties that troubled network security management personnel. Based on previous studies, further proposed a double attack graph based on domain equipment. By the underlying network topology data collected and analyzed, using Bayesian theory to complete the quantify for the double attack graph and generation strategy in minimal power key set, with the cost of calculation of key equipment in the automatic recognition network topology, we provide an important basis for network maintenance. Experimental results show that the measure of using quantitative domain equipment double attack graph to recognize the intrusion intention is not only effective and feasible, but also has the feature of easy promotion.