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This thesis focuses on temperature measurement of elements of high-voltage equipment using fiber Bragg grating sensing technology. During long-term operation, high-voltage equipment may experience local overheating caused by conductor loss, insulation aging, poor electrical contact, or partial discharge. Such temperature rise can indicate abnormal operating conditions and may accelerate insulation degradation and fault development. Traditional electrical temperature sensors are easily affected by electromagnetic interference and may create insulation safety problems in high-voltage environments. In contrast, optical fiber sensors have good electrical insulation, strong electromagnetic interference resistance, and long-distance signal transmission ability.In this work, the principles of optical fiber sensing and FBG temperature measurement were analyzed. A metal sphere-gap discharge structure was used to simulate a high-voltage discharge environment, and the stability of a bare FBG sensing head was studied under different voltages and distances. During the tests, transient spike interference appeared in the measured signal when discharge occurred, while the signal baseline remained stable without obvious continuous drift. This confirms that the FBG sensing system can maintain good stability in a high-voltage discharge environment. To develop a simple and low-cost temperature measurement method, a semiconductor laser was used as a scanning light source, and laser heterojunction voltage was used to represent the wavelength scanning state. Since the voltage change was weak, an LM358-based amplifier circuit was designed. Calibration experiments in a temperature chamber demonstrated an approximately linear relationship between FBG temperature and laser heterojunction voltage, with a verification error of about 0.4 °C. Optical losses in the assembled system were also measured, including fiber cable loss, fusion splicing loss, and splitter loss. Finally, the FBG sensor was placed in a high-voltage surface discharge area to verify the possibility of measuring insulation surface temperature. The obtained data confirm the application potential of FBG sensing technology for temperature measurement of high-voltage equipment elements.