Abstract: The abnormal temperature will lead to the occurrence of mine fire and major accidents, for this purpose, the distributed optical fiber temperature measurement technology is used to realize the online monitoring and early warning of mine temperature. The temperature coefficient of the optical fiber cable is calibrated by an indoor experimental device, and the temperature measuring system is arranged in 61101 air return way in a coal mining area and the online monitoring was conducted for more than half a month. The test results showed that the temperature variation curves processed by this temperature measurement technology could accurately reflect the trend of the temperature variation in the roadway, the regional abnormal spots on the curve could be used as the basis for accurately judging the abnormal position of the temperature; 700 m long line layout system could well adapt to the site environment, the amount of data is rich and reliable, and the characteristics of the curve is obvious. This temperature measurement technology is of high positioning accuracy and reliable operation and can be used for long distance temperature monitoring and meet the needs of mine temperature monitoring.