This study aims to safeguard the stable import supply of crustacean aquatic products in China and mitigate risks associated with the global trade network. Based on global crustacean trade data from 2014 to 2023， this paper constructs a directed weighted network to analyze its structural evolution characteristics. A comprehensive centrality indicator is developed to identify core countries within the network. The SIR epidemic model is employed to simulate the trade risk propagation process and identify specific propagation paths. The findings reveal that the global crustacean trade network from 2014 to 2023 exhibits small-world properties， with an overall trend toward structural integration and enhanced regional agglomeration. A distinct bipolar structure led by China and the United States is evident， with China surpassing the United States in 2022 to become the core node of the network. Ecuador's status has risen significantly， while the status of Indonesia， Thailand and Japan has declined. Core countries differ in their risk propagation capacity， with the United States， Ecuador， Canada， and India exhibiting strong initial capacity， while Denmark and Norway demonstrate the weakest. The research indicates that： （1） The structure of the global crustacean trade network is significantly influenced by external shocks， with dynamic adjustments in the status of core countries. China has gradually emerged as the most influential hub within the network. （2） Core countries' risk propagation capabilities exhibit heterogeneity， categorized into burst， progressive， restricted， and low-impact， with China classified as a restricted source. （3） Although China has become a core hub， its import sources remain concentrated and export network depth is limited， necessitating diversified import channels and optimized export network structures to enhance supply chain resilience.