Capacitive device medium loss angle online monitoring device

Disclosed is a capacitive device medium loss angle online monitoring device which comprises a remote monitoring center, a server and a monitoring terminal. The remote monitoring center is used for transmitting acquisition commands to the server, receiving data returned from the server, analyzing, calculating, diagnosing operating condition of a capacitive device, early warning failure and storing received data returned from the server into a databank; the server is used for transmitting the acquisition commands transmitted by the remote monitoring center to the monitoring terminal and transmitting received data transmitted by the monitoring terminal to the remote monitoring center; and the monitoring terminal is used for receiving the acquisition commands transmitted by the server, acquiring signals of leaking current in the running process of the capacitive device and other relevant information, converting acquired current signals and other relevant information into data, storing the data and simultaneously transmitting the data to the server. The monitoring device can realize failure diagnose for insulation state of high-voltage devices when in online real-time monitoring for relative medium loss angles of the capacitive device.