Abstract: In order to explore the effect of long-term addition of organic materials on the physical properties of tobacco-planting soil in central Henan, based on a long-term positioning experiment conducted in Zhengzhou Science and Education Park of Henan Agricultural University, five treatments were established: no fertilizer (NF), nitrogen, phosphorus, and potassium (NPK), NPK plus wheat straw (NPKS), NPK plus planting and incorporation of ryegrass (NPKG), and NPK plus tobacco stalk biochar (NPKB). Soil bulk density, penetration resistance, soil moisture content, and soil aggregate distribution were measured in 2024. The results showed that long-term addition of organic materials consistently reduced soil bulk density and penetration resistance, with NPKS showing the best effect, reducing post-harvest values by 10.36% and 16.40%, respectively, compared to NPK treatment. Long-term addition of organic materials improved soil water-holding capacity, significantly increasing post-harvest capillary water-holding capacity, field water-holding capacity, and volumetric water content. Overall, the NPKB treatment showed a better effect. Long-term addition of organic materials also significantly increased the content of post-harvest mechanical aggregates >5 mm and water-stable aggregates >1 mm, and improved the stability of mechanical aggregates and water-stable aggregates, with the NPKS treatment showing the best overall results. After long-term addition of organic materials, soil bulk density showed a significant negative correlation with field water-holding capacity, and a highly significant negative correlation with the mean weight diameter and geometric mean diameter of water-stable aggregates. Soil capillary water-holding capacity and field water-holding capacity showed significant positive correlations with the mean weight diameter of water-stable aggregates and the mass fraction of water-stable aggregates (>2 mm), while soil volumetric water content showed a highly significant positive correlation with the mean weight diameter and the mass fraction of water-stable aggregates (>2 mm). Path analysis results showed that the mass fraction of water-stable aggregates (>0.25 mm) and the mean weight diameter directly limited soil bulk density. The mean weight diameter limited soil bulk density primarily through the geometric mean diameter, the mass fraction of water-stable aggregates (>0.25 mm), and the mass fraction of 1-2 mm aggregates. Similarly, the mass fraction of water-stable aggregates (>0.25 mm) limited soil bulk density mainly through the mean weight diameter, the geometric mean diameter, and the mass fraction of 1-2 mm aggregates. In conclusion, long-term addition of organic materials can optimize soil structure, with wheat straw incorporation showing the best effect.