Abstract: In order to ensure the safety of oil transportation facilities, a fully automatic wireless break alarm device for cathodic protection system is developed. On the basis of PS-1 potentiostat, alarm signal extraction circuit, radio communications and automatic control technology, functions and working principles of modules in the device are described. This device transmits and receives signals by a wireless remote control device using changes of anode output voltage to determine whether theft occurs. During the experiment, the alarm device reaches a 100% alarm accuracy without false alarms. Field test results show that the device can effectively protect oil facilities and achieve expected results.