摘要： Transformer is an important link of power system, and its operation state directly affects the security and stability of power system operation. With the continuous development of the national economy and the continuous improvement of the people's needs, the power grid load has been continuously improved, and the capacity of the transformer has been continuously expanded, and the accident rate has increased accordingly. According to related statistics, more than 66 kv transformer of the world's average accident rate over 0.89%, especially for winding in transformer winding overtemperature operation, result insulation aging and breakdown, accident of burning large ratio (according to the statistics, about 80% of the accident rate above). For oil-immersed power transformer, the time depends on the service life of solid insulating materials (fiber paper), prompting insulation materials is the main factor of aging temperature, moisture and oxygen, heat effect of transformer insulation aging is the decisive factor, therefore the transformer internal main parts (winding and iron core, the place such as insulating oil) temperature decides the service life of the transformer temperature due to the electric power equipment testing environment with high voltage and strong electromagnetic interference, and space is narrow, the traditional method cannot directly on the power equipment temperature state of online measurement, and a new temperature measuring system based on semiconductor optical fiber sensing technology has small volume, good insulation, good resistance to electromagnetic interference, temperature measurement consistency, can be directly installed on the transformer and other power equipment inside, can accurate and fast reflect the change of the internal temperature of main components of power transformer, the transformer winding and iron core, the place such as insulating oil temperature real-time online measurement.