Being as a significant section of security issues in Wireless Mesh Network (WMN), the research and application about Intrusion Detection System (IDS) in WMN are just getting start. The characters and requirements for IDS in WMN are described and analyzed firstly; Based on the Hierarchical Proxy-based Topology (HPT) structure in Mesh network, an efficient proxy-based IDS scheme is proposed, the working flow of proxy-based IDS in WMN is also designed, in which, the functions about five modules are illustrated. Compared with traditional IDS in wire or wireless network, there are two new types of nodes, Proxy and Central Console, to be added in our proposed scheme, in addition, efficient multi-level hierarchical grouped topology structure is adopted, which can provide better security protection for the wireless Mesh network.