A new kind of transparent rock-like materials was developed for studying crack propagation inside instated of rail rock. It that have artificially induced internal cracks was tested under uniaxial compression. This experiment observed the overall process of the pre-test specimens fractured completely destroyed, analyzed each stage of the presentation of the crack propagation characteristics carefully and summarized the law of pre-crack damage the specimen. The experiment studied the effect of different lengths of fissure on basic physical and mechanical parameters;obtained the greater the crack length, uniaxial compressive strength and elastic modulus of the specimen are lower conclusions. These studies have important guidance for the early warning of geotechnical engineering works.