Abstract: Aiming at the demand for the simultaneous monitoring of key parameters including temperature and vibration of steam turbine high-pressure cylinder inlet pipe in nuclear power plants under complex operating conditions, this paper investigates the simultaneous temperature and vibration monitoring technology based on Fiber Bragg Grating (FBG). A temperature calibration experimental platform was designed and constructed to temperature measurement, which verified the stability and repeatability of FBG sensors in high-temperature environments. Combined with the measured data of steam turbine high-pressure cylinder inlet pipe in a nuclear power plant, a method integrating wavelet analysis and Fast Fourier Transform (FFT) was adopted to decouple the temperature and the vibration characteristics of the pipelines under different operating conditions were systematically analyzed. The research results indicate that FBG sensors can effectively monitor the pipeline temperature and vibration, which provides reliable support for the further optimal operation and fault diagnosis of the relevant systems.