Abstract: Wavelength-shift detection is the key technology of fiber Bragg grating sensor. Several techniques have been developed for demodulation of fiber Bragg grating sensor, such as passive demodulation, matched grating pairs detection,interferometric detection, etc.Various methods for wavelength-shift detection of FBG sensor are described in detail.The principle of all these methods are analyzed. The non-balanced Mach-Zehander interferometer and tunable narrow band light source detection methods are described emphatically. Their advantages and disadvantages are discussed as well.