Transmission line icing online monitoring system

The invention relates to a transmission line icing online monitoring system. The system comprises a transmission line icing online monitoring device and a transmission line icing monitoring center which are connected with each other, wherein the transmission line icing online monitoring device comprises a sensor unit, a master controller unit, a communication unit and a power supply unit, the power supply unit is respectively connected with the sensor unit, the master controller unit and the communication unit, and the master controller unit is respectively connected with the sensor unit and the communication unit; the sensor unit comprises a tension sensor, a two-dimensional tilt angle sensor, a three-dimensional ultrasonic wind speed and direction sensor and a temperature and humidity sensor, the tension sensor is arranged between a transmission line iron tower and an insulator string, the two-dimensional tilt angle sensor is fixed to the tension sensor, and the three-dimensional ultrasonic wind speed and direction sensor and the temperature and humidity sensor are respectively fixed to a cross arm of a transmission line. Compared with the prior art, the system has the advantages of being high in monitoring accuracy and reliability and the like.