Abstract:The splashing of raindrops causes the fragmentation of soil aggregates and the clogging of pores, resulting in the decrease in soil permeability. To explore the changes in soil structure and infiltration capacity under raindrop splashing and provide reference for predicting soil erosion conditions under raindrop splashing, the research explored the relationship between surface soil pore structure and soil permeability under rainfall conditions, using the raindrop splash experiment, soil infiltration experiment and synchrotron radiation CT scanning technology. The results indicate that: (1) raindrop splashing significantly reduces the total porosity and permeability coefficient of the soil (P<0.05). The total porosity of soil decreased by 20.64 %, 36.05 % and 44.88 %, respectively, and the soil permeability coefficient decreased by 15.69 %, 40.42 % and 71.77 %, respectively, after the splashing of raindrops with diameters of 2.67 mm, 3.39 mm, and 4.05 mm. The fragmentation level of soil pores intensifies after raindrop impact, leading to a more irregular shape of the pores and reduced connectivity. (2) The size, shape and connectivity of soil pores had significant effects on soil permeability (P < 0.01): The larger the pores and the more regular the shape, the greater the impact on soil permeability. From the perspective of pore connectivity, the radius of connected pore throats and the porosity of the soil have the greatest impact on infiltration capacity. On this basis, a predictive model was established for the soil permeability coefficient (K) in relation to the total porosity(TP), macroporosity rate (Vlp), regular porosity rate (Vrp), connected porosity rate (Vcp), and pore throat radius (Rth): K=0.402TP+0.104Vlp+0.1401Vrp+0.350Vcp+0.003Rth-0.415,R2=0.93,p<0.05. In summary, raindrop splashing alters the size, shape, and connectivity of soil pores, leading to the disruption of soil pore structure and a decrease in soil infiltration capacity.