Based on the theory of fiber Bragg grating sensing,and using a 2 m plane stress material model of the simulation experiment,the wavelength shift regulations of fi- ber Bragg gratings under rock settlement deformation conditions were got,which provided reliable basis for the design of the wavelength bandwidth of sensing gratings.The wave- length increase when the rock layers are under tension,and decrease under compression. Compressive strain sensitivity is bigger than tensile strain sensitivity when the load is lower.However compressive strain sensitivity is smaller than tensile strain sensitivity when the load is higher.Experimental result coincides well with theory.The wavelength band- width of two neighboring fiber Bragg gratings of the gratings used for monitoring the de- formation of rock layer should be no less than 6 nm.An effective new approach for de- tecting the deformation of rock settlement with fiber Bragg gratings is provided. Based on the theory of fiber Bragg grating sensing, and using a 2 m plane stress material model of the simulation experiment, the wavelength shift regulations of fi- ber Bragg gratings under rock settlement deformation conditions were got, which provides reliable basis for the design of the wavelength bandwidth of sensing gratings.The wave- length increase when the rock layers are under tension, and decrease under compression. Compressive strain sensitivity is bigger than tensile strain sensitivity when the load is lower. when the load is higher. Experimental result coincides with the theory. The wavelength band-width of two neighboring fibers Bragg gratings of the gratings used for monitoring the de- formation of rock layers should be no less than 6 nm. An effective new approach for de- tecting the deformation of rock settlement with fiber Bragg gratings is provided.