【Objective】 Straw incorporation is a vital agricultural practice that positively impacts soil structure improvement, erosion mitigation, and fertility enhancement. Given the increasing pressure on agricultural systems to maintain high productivity while minimizing environmental degradation, scientific evaluation of soil quality under straw incorporation holds significant implications for advancing efficient straw utilization and achieving high crop yields. Soil quality assessment can guide farmers and policymakers in optimizing straw use efficiency, thereby supporting long-term crop productivity and ecological sustainability. This study focuses on evaluating the effects of different straw management strategies on paddy soil quality under a rice-rapeseed rotation system. It aims to analyze the impact of straw incorporation methods on soil physicochemical properties and elucidates the mechanisms of straw incorporation through soil quality assessment, providing theoretical support for sustainable soil management in rice-rapeseed rotation systems. 【Method】 To study the impact of straw incorporation on soil quality, three straw management practices were implemented: no straw return (CK), straw mulching (T1), and straw plowing (T2). Field experiments and laboratory analyses were conducted to assess differences in soil aggregate stability, nutrient distribution, and stoichiometry. The soil quality index (SQI) was calculated using the minimum data set (MDS) method while pathway analysis was employed to explore the mechanisms by which soil physicochemical factors affect soil quality. 【Result】 The results revealed that (1) Compared with the CK and T2 treatments, straw mulching significantly increased the content of soil >1 mm water-stable aggregates. The mean weight diameter (MWD) and geometric mean diameter (GMD)of soil aggregates increased by 6.60% and 23.58%, respectively, indicating that straw mulching enhanced structural stability.(2)T1 increased the organic carbon content of aggregates with different particle sizes, among which the nutrient levels of 2～1 mm aggregates were the highest. Notably, the >5 mm aggregates demonstrated the greatest nutrient contribution capacity, highlighting their role in long-term carbon sequestration. (3) T1 significantly increased the carbon-nitrogen ratio (C/N) and the carbon-phosphorus ratio (C/P). On the contrary, these ratios decreased under T2. (4) The soil quality assessment results based on the MDS revealed that T1 achieved the highest SQI, which was superior to CK and T2 whereas pathway analysis demonstrated that the direct influence of aggregate stability on SQI was the strongest (path coefficient = 0.681). 【Conclusion】 Straw mulching optimizes soil quality by promoting the formation of large aggregates, enhancing aggregate stability, improving organic carbon sequestration, and balancing ecological chemometrics. It is the most effective strategy for improving soil health in rice-rapeseed rotation systems. In contrast, the benefits of straw plowing are limited, possibly due to carbon loss caused by disturbance. These findings provide farmers with actionable insights, indicating that straw mulching should be prioritized over plowing to maximize soil quality.