The invention discloses a monitoring device of an electric power communication cabinet based on TCP / IP (Transmission Control Protocol / Internet Protocol) communication. The monitoring device comprises a source supply unit, a monitoring unit and a transmission unit both which are respectively connected with the source supply unit; electricity supplied by an interchanger POE (Power Over Ethernet) is used as main power supply, Ethernet is used as a data transmission passageway, and all sensing nodes are based on an embedded data converging platform composed of single chips, collected temperature and current information are converted into digital signals, and data are transmitted to monitoring software through TCP / IP protocols. Meanwhile WEB pages are built in the monitoring device and display currently collected temperature data and operation current data, the monitoring software cannot be fixed to some host, monitoring data on each node can be acquired when any networked host operates the software, a server isn't required to be specially erected, and the monitoring device is simple in arrangement and convenient to use.