In this paper, the security issues in the interlinkage between Ad Hoc networks and lineate networks are investigated. An intrusion detection system for the interlinkage between two networks is established and a model which can realize the interlinkage between Ad Hoc and lineate networks is presented. This scheme is based on combination of misuse detection and anomaly detection. It combines the two technologies to reduce the false positive rate and the false negative rate in only one detection technology, and then security of intrusion detection system is improved.