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 and straw-on soil structure and hydraulic properties. Compared with chemical fertilizer alone (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 (θs) relative to the no-fertilizer control (CK). However, compared with NPK, the combined application of organic and inorganic fertilizers (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 (R0.25) (P< 0.05). MWD was positively correlated with both R0.25 and the soil wilting coefficient, while R0.25 was positively correlated with field capacity (FC) (P< 0.05). These findings provide preliminary insights into how exogenous 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.