A fast fiber Bragg grating (FBG) sensing system with large capacity based on marshalling measurement and edge filter is designed. Sensing gratings in traditional time division multiplexing systems are grouped according to their positions on the fiber, and these grating groups are then successively measured. The limit of detector′s dynamic range in single measurement is avoided, the reutilization of sensing gratings is realized, and the measuring distance is extended. Meantime, by using edge filtering method, fast wavelength demodulation is achieved, and the wavelength signals of all gratings in one grating group is measured once, which can reduce measurement time and improve the scanning frequency of the system effectively. The result shows that a demodulation linearity of 0.9913 is realized in the temperature sensing test of the system and the error is less than 1.36 ℃.