" Laboratory for Ultrafast Transient Facility" is organically composed of two major categories of core parts: one is a Ultrafast Transient electron microscope cluster; the other is a Ultrafast Transient synchrotron radiation device that provides ultraviolet to X-rays. The first stage of synchrotron radiation device includes a 0.5 GeV linear accelerator as full energy injector, a high-current storage ring, and a beam line. For the construction of the linear accelerator beam diagnostics system, the main focus is on the reliability and maintainability of the system. The system mainly includes beam position measurement system , bunch charge measurement system and beam profile measurement system; the article will mainly introduce the composition and design of these systems.