【Objective】This study aimed to clarify the effects of organic-inorganic regulating material mulching on the pore structure of saline-alkali topsoil and select suitable mulching materials for crop seed germination.【Method】Four experimental treatments were set up, namely CK (native soil), JX1 (composted cow dung + (a mixture of HA, CaO, MgO, SiO?, and Na?SeO?)), JX2 (spent substrate + (a mixture of HA, CaO, MgO, SiO?, and Na?SeO?)), and JX3 (composted straw + (a mixture of HA, CaO, MgO, SiO?, and Na?SeO?)). A field operation involving digging V-shaped ditches→sowing→applying amendments→rolling was adopted. Soil structure and its pore characteristics were analyzed using micro-computed tomography (micro-CT) scanning, combined with field experiments and mathematical statistical analysis.【Result】The results showed that all treatments reduced soil bulk density and improved soil water capability and saturated hydraulic conductivity. Specifically, the saturated hydraulic conductivity of JX2 and JX3 was 2.4 times that of CK, and their soil water capability increased by 17.8%–19.5%. In terms of pore structure, different mulching material significantly affected the quantity and distribution characteristics of soil pores: The JX2 and JX3 showed significantly increased total porosity and connected porosity, while JX1 had lower total porosity; JX3 was dominated by macropores with fewer micropores, whereas JX2 had a more balanced pore size distribution. Comparison of pore structure parameters revealed that JX2 and JX3 had similar values of fractal dimension, anisotropy, and circularity ratio, but the Euler number of JX2 was significantly lower than that of JX3. This indicated that both treatments enhanced the complexity and stability of the pore structure, and JX2 had better pore connectivity. These pore structure optimizations significantly improved the microenvironment for seed germination, thereby increasing the emergence rate and improving the seedling growth traits of foxtail millet, with JX2 showing particularly notable effects.【Conclusion】In conclusion, Organic-inorganic amendment mulching can enhance soil structural performance by optimizing the pore characteristics of saline-alkali soil and create a suitable soil microenvironment for crop seed germination. Among the tested materials, the spent mushroom substrate residue-based (JX2) and straw-based (JX3) regulating materials showed showed the most significant effects.effects, These combinations are effective technical approaches for efficiently regulating the microenvironment of coastal saline-alkali soil and breaking surface soil compaction.