【Aim】 Bromus diandrus is indigenous to the Mediterranean region and is an important weed in agricultural ecosystems in many countries. B. diandrus is frequently found in imported agricultural products in Chinese ports. Accordingly, it is necessary to conduct a pest risk analysis. 【Method】 Following the pest risk assessment protocol, qualitative and quantitative analyses of the invasion risk of B. diandrus were evaluated, a comprehensive risk value (R) wan calculated, and the risk level was determined. 【Result】 B. diandrus is a strong invader and has rapid colonization abilities, with a R of 2.12. 【Conclusion】 B. diandrus is considered a high-risk weed. The port quarantine department should strengthen the inspection and field monitoring of B. diandrus in imported agricultural products to ensure timely discovery and eradication.