In order to explore the effect of soil bulk density on the water infiltration capacity under surge-root irrigation (SRI) in red soil regions, a experiment of water infiltration was carried out under different soil bulk density levels of red soil for SRI in soil bins. The results showed that the bulk density had a significant effect on soil infiltration capacity. With the decrease of soil bulk densities,wetting front migration, the cumulative infiltration and the infiltration rates showed increasing trends. The smaller the bulk density was, the greater decrease occurred. The wetting front migration, the cumulative infiltration and the steady infiltration rates and soil bulk densities were negatively correlated as power functions. For the same depth soil layer, the smaller the soil moisture content was observed in the larger the soil bulk density. The effect of bulk densities on the water content distribution was gradually weakened during the water redistribution process. The Kostiakov infiltration model showed that the initial infiltration rates of the soil decreased with the increase of bulk densities. Under the greater the bulk density, the infiltration capacity decreased more fastly. This research could lay the foundation for the popularization and application of SRI technology in red soil areas.