Abstract: In response to the complex environment of wind farms and the difficulty in comprehensively monitoring the joints which are prone to defects, this paper studies a distributed optical fiber temperature sensing system (DTS) based on Raman scattering and optical time-domain reflectometry (OTDR) technology. By designing a high-sensitivity and long-distance monitoring system and deploying it on-site in a wind farm, real-time temperature data along the cables were successfully obtained. The analysis results show that the system can clearly capture the distribution patterns of cable temperatures with changes in power generation output, geographical environment, and seasons, accurately locate abnormal temperature sections, and verify its excellent real-time monitoring and early warning capabilities in engineering practice, providing an effective technical solution for the condition assessment and fault prevention of wind farm cables.