Abstract.To improve the overhead transmission line online monitoring device power utilization rate, the online monitoring device is not always collecting data, according to the different operational characteristics of the device units, proposed a comprehensive efficient energy-saving control scheme. Scheme given priority to the adoption with output enable efficient DC-DC converters to provide power for each device, used COMS tubes as the electric control switches for sensors and other high power devices, data acquisition used the strategy of each sensor successively turn on the power, the remote communication went online method combination of serial data trigger and short message trigger, used the controller with low power standby mode, and used the transmission line icing online monitoring device as an example to show the corresponding calculations and tests. The tests show that the test results consistent with the calculated results, using this energy-saving control scheme can effectively reduce the solar panel and battery capacity and volume, improve the power supply reliability, prolong the service life, and reduce the device cost and maintenance cost.