With the gradual popular networks, local area networks within the framework of such a small share of the resources of small computer network has been more attention, it not only shared among networked computer programs, documents and other resources without having to return diskette transfer ; can also, through the network to multiple computers sharing the same hardware, such as printers, modems, etc. At the same time, we can use a computer network to send and receive fax, convenient and economical. The graduation design will be the main topic of small LAN to be used in the construction of the various technical and implementation options for the design direction, the construction of small LAN and provide a theoretical basis and practical guidance.