Integrated application of organic and chemical fertilizers has emerged as a critical practice for sustainable soil fertility management. Based on a 16-year field experiment with six fertilization treatments at the Yanting Agro-Ecological Station of Purple Soil, Chinese Academy of Sciences, this research examined the effects of two exogenous organic materials (pig manure compost, OM; and rice straw, RS) on soil structure and hydraulic properties. Compared with chemical fertilizer treatment (NPK), the addition of organic materials (OMNPK and RSDNPK) improved soil structural quality by increasing the proportion of large aggregates (>2 mm) and enhancing aggregate stability. Fertilization treatments increased soil macroporosity and saturated water content (θ_s) compared to the no-fertilizer control treatment (CK). However, compared with NPK, OMNPK and RSDNPK reduced macroporosity while improving soil water retention capacity. Straw application alone (RSD) had no significant effect. Correlation analysis revealed that soil structural quality (Sq) was significantly negatively correlated with both the mean weight diameter (MWD) of aggregates and the proportion of macroaggregates (R_0.25) (P<0.05). MWD was positively correlated with both R_0.25 and soil wilting coefficient, while R_0.25 was positively correlated with field capacity (P<0.05). These findings provide preliminary insights into how organic amendments affect the structure and hydraulic behavior of purple soil, offering a theoretical basis for future research on their role in key ecological processes underlying long-term soil improvement.