Abstract: Scattered radiation, which seriously decreases the precision of image reconstruction in high energy flash X-ray radiography, can be largely diminished by anti-scatter grid. The design aim of MeV anti-scatter grid is firstly presented, and the radiographic system layout and the imaging system are given using theoretic analysis. Then parameters of anti-scatter grid, such as the total thickness, aperture and space between holes, and the thickness of W thin foil with small holes, are detailed using Monte Carlo simulation and analysis. Effects of the machining error and imperfect alignments of radiographic components on the performance of MeV anti-scatter grid are also discussed, and design parameters of the prototype of anti-scatter grid are presented. With the designed anti-scatter grid, the