A compact and high-resolution multiplexed Fiber Bragg Grating (FBG) wavelength interrogation system was reported. A compact tunable Laser Diode(LD) covering wavelength from 1 546 nm to 1 558 nm is applied as the light source to improve the simplicity, wavelength resolution and the response rate of the FBG demodulation system. A standard HCN gas-cell is incorporated as the wavelength reference. The 1 pm quasi-continuous wavelength tuning of the LD over 12 nm is realized by the combination of current control on multiple electrodes. A spectral centroid algorithm is used to determine the FBG′s wavelentgth, which results in robustness of the demodulation and then the high accuracy of the FBG interrogation. The demodulation process is simulated. The experimental results show an excellent wavelength resolution of better than 1 pm and precision of about 2 pm, which corresponds to temeprature resolution of 0.1℃ around 1 550 nm in an FBG -based fiber sensor.