The invention provides a light pipe device and a projection system comprising the light pipe device. The projection system has an optical machine which comprises a body and the light pipe device. The light pipe device comprises a light pipe, a mounting bracket, a framework and a positioning device, wherein, the light pipe has a central shaft, the mounting bracket is connected with the body of theoptical machine, the framework is fixedly connected with the mounting bracket, the light pipe is arranged inside the framework, and the positioning device arranged between the framework and the mounting bracket provides at least one pushing force actually perpendicular to the central shaft, thereby enabling the framework to make axial displacement actually in parallel with the central shaft relative to the body.