详细阐述VLAN的应用优势及划分策略,对VLAN间的通讯和中心第三层交换机的原理及应用优势进行科学分析,进而提出基于中心第三层交换VLAN是图书馆大型网络体系的一个最佳选择;着重从多层交换网络体系的构建、VLAN的合理规划、采用安全有效管理策略三个方面,对图书馆Intranet体系的构建进行探讨。 This paper elaborates the application advantages of VLAN and the strategy of partitioning, and makes a scientific analysis of the principle and application advantages of the communication between VLANs and the third layer switch of the center, and then puts forward that VLAN switching based on the third layer in the center is the best choice for large-scale library network system. ; Focusing on the construction of multi-layer exchange network system, the rational planning of VLAN, the use of safe and effective management strategies in three aspects, to explore the construction of library Intranet system.