A novel type of quasi-distributed fiber Bragg grating sensing system based on fiber chaotic laser is demonstrated. The light source is the wavelength tunable chaotic fiber laser. The identical weak fiber Bragg gratings are utilized as the sensors. According to delta function characteristics of the correlation of chaotic light sources, the correlation peaks of the cross-correlation between the reflected light from sensors and reference light from chaotic fiber laser can locate the positions of the sensors. The center wavelength of the identical weak fiber Bragg grating with stress can be demodulated by using tunable optical fiber grating filter and the quasi-distributed fiber Bragg grating sensing system is realized. The experimental results show that the single fiber link of the identical fiber Bragg grating sensor using the tunable chaotic fiber laser is realized and it is expected to achieve the intensive weak fiber grating sensing network.