Abstract: The article is in view of the high failure rate of mine pit electrical network, the difficult of Inquiring failure and so on shortcoming, develops one kind of intelligent synthesis protective device to use in the mine pit electrical network system. This equipment may carry on the real-time monitor and the protection to the mine pit electrical network, may effective prevent the electrical network breakdown the further worsening; Its perfect breakdown recognizer and the inquiry way, are advantageous to the breakdown rapidly removes. The using of blue tooth technology causes the equipment of the reliability, the anti-jamming as well as the flexibility all obtains the very big enhancement.