Telescope is a very important tool for astronomers to survey and study the stellar stars and astronomical phenomena. The performance of a telescope is its capability to track the observing objects and keep the image on the field of view during the observing period. All these functions will be achieved by telescope mount, including mount control system. The mount is to support the mirror cell and keep the mirror cell position stability. Meanwhile, with the help of control system, the mount acts as tracker of the observing objects. So, for a telescope, the mount and its control system play an important role during the telescope operation. This paper introduces the structure design and analysis of the mount system of a 2.5m optical/infrared telescope, such as azimuth axis, elevation axis, M2 positioning system, M3 positioning system, and so on. Especially, an innovative support and escape mechanism of M3 will be proposed and analysed in this paper.