(This design combines the actual needs of a small and medium-sized enterprise network, through simulation research on the design of the network construction scheme, the design of the security-based network configuration scheme, the design of the server setup scheme, and the enterprise network security design, etc. Key issues encountered while designing the design. It mainly includes requirements analysis, network equipment selection, logical network design, IP address design scheme design, server setup and network security design. The thesis designs and analyzes the network topology of small and medium-sized enterprises, carries out network simulation configuration and security design through Cisco PacketTracer software, and provides a network design and design solution.)