The impact of sand grain on sandy bed surface is not only one of the main processes of near-surface aeolian sand movement, but also the main cause of sand surface damage and soil erosion. In this study, we first simulate the process of grain-bed impact and splash of sand grains with different sizes on sand bed surface using the discrete element method. Then we analyze the relationships among the number, speed and angle of splashing grains and the speed and angle of the impacting sand grain with different slopes. Finally, we present the splash function of the takeoff speed and angle of splashing grains with the incident speed and angle changing and give their probability density distributions. This research is of great importance to understand the windblown sand movement on sand dune or ripples. (C) 2017 Elsevier B.V. All rights reserved.