In the modern industrial control systems, due to the needs of distribution and intelligent of system, industrial Ethernet is widely used. Transmission, control and transform of information are usually based on the form of switching signals. This paper presents a design of Ethernet switching signal monitoring terminal. The terminal software is based on embedded operating system μC/OS-Ⅲ and embedded TCP/IP protocol stack μIP, the function of network address and port configuration is embedded in the software. The terminal hardware is based on ARM core MCU LPC2106, with a photo-coupling method used for the isolation of the switch signal. This developed terminal with the advantages of universal, reliable and expandable characteristics can be connected to Ethernet for configuration and switching signal monitoring flexibly, and it has the significant potential for use in the various applications such as industrial control and smart home.