The invention discloses a transmission line anti mountain fire early warning system, including a data collection system, a transmission and control system and a background management system. The datacollection system includes an infrared thermal imaging camera, a temperature sensor, a humidity sensor, a wind speed sensor, a wind direction sensor, a visible light camera, a light sensor and a smokesensor. The transmission and control system includes a central controller. The background management system includes a background server and an alarm. The infrared thermal imaging camera, the visiblelight camera, the temperature sensor, the humidity sensor, the wind speed sensor, the wind direction sensor, the light sensor and the smoke sensor transmit the collected data to the central controller through signals. The central controller further processes and sends the signals to the background server. The background server can trigger the alarm to alarm according to the received signals. Thebackground server can feed back to the central controller according to the received signals so as to control the infrared thermal imaging camera and the visible light camera.