Flash X-ray diffraction imaging system based on flash X-ray generator (TD-450S of Scandiflash AB) and imaging plate was designed to measure microscopic response in shock wave compression studies. Due to intense Bremsstrahlung radiation, continuous X-ray generator and HPGe detector were used to regulate diffraction optical path. Diffraction signal of LiF single crystal was recorded using flash X-ray tube with molybdenum as the anode material under ambient conditions and shocked state. Results show that flash X-ray diffraction imaging system described here is useful for examining structural changes in shock compression experiments and temporal resolution is 25 ns.