The existing intrusion attack source location methods have low location accuracy and laser communication network attack detection accuracy because the database is not perfect. Therefore, a laser communication network intrusion attack source location method based on knowledge map is proposed. The knowledge map of laser communication network is constructed, and the characteristics of laser communication network are analyzed. The attack detection of network samples is carried out by using hierarchical clustering algorithm, including hierarchical clustering algorithm, iterative clustering algorithm, optimal scheme selection, and network attack detection. The abnormal data in laser communication network is obtained. According to the abnormal data detection results, the abnormal data location is preliminarily located by trilateral positioning method. Finally, the intrusion source location of laser communication network is realized by improving particle swarm optimization algorithm. Experimental results show that the proposed method can accurately locate the coordinate position of the attack source, and the laser communication network attack detection accuracy is high.