Enhancing pod shatter resistance is essential for improving the mechanical harvesting efficiency of rapeseed (Brassica napus L.). This study aimed to evaluate pod shatter resistance in domestic breeding lines and genetic resources, as well as to investigate the relationship between shatter resistance and agronomic traits thereby providing foundational data for the development of shatter-resistant cultivars. Pod shatter resistance was assessed using the Random Impact Test for 105 accessions in 2022–2023 and 159 accessions in 2023–2024, with the Silique Shatter Resistance Index (SSRI) as the evaluation criterion. Most accessions exhibited susceptibility to pod shatter, whereas IT031375 showed high shatter resistance, identifying it as a promising resource for the development of shatter-resistant cultivars. Analysis of the relationship between weather conditions and pod shatter resistance revealed that longer sunlight exposure and lower precipitation during the growing stages contributed to improved pod development and shatter resistance. Furthermore, a correlation analysis between SSRI and agronomic traits demonstrated significant positive correlations with silique length (r=0.368, p<0.001) and weight (r=0.451, p<0.001). Increased silique length and weight are associated with enhanced pod wall development and seed weight, which are critical for improving yield and shatter resistance.