A program for the ray-tracing of cylindrically Laue bent crystal is developed based on the lamellar model of X-ray geometrical diffraction. The program is compiled by C and runs under the computing environment VC++. It is used to simulate different projects of the direction and energy band of the diffracted rays. The results show that the program is exactly correct on the trace of rays according to the excellent agreement between the simulations and theoretical calculation (or experimental results). Study of the X-rays′ path (in and out) and energy band which can be diffracted by making use of this ray-tracing program, we obtain the optical properties of Laue bent crystal such as focusing, collimation and dispersion. It is useful for the research and application of Laue bent crystal.