Electric vehicles have a good development market due to their advantages in energy conservation and environmental protection, which has played a sustained high growth driving effect on the lithium power battery industry. This has prompted countries to consider the safety of the electric vehicle lithium battery(EV LIB) supply chain. In the context of globalization, complex supply relationships and inevitable cross-border cooperation have increased the vulnerability of the global EV LIB supply chain network. Safe and reliable access to EV LIB related products has become a major concern for countries. Therefore, this article proposes a risk propagation model for the global EV LIB supply chain network considering trade relationship agreements based on multi-layer complex networks, revealing the scale and path of risk propagation for key risk sources. It can be observed that the propagation of risks is influenced by trade relationship agreement, which can amplify the scale of risk transmission in some key countries. China and South Korea play a crucial role in the positive electrode network and lithium battery network, and can mitigate the cascading effects of risks by improving their trade relationship agreemens with some key upstream countries. When supply restrictions occur in Chile in the lithium trade network, the best mitigation strategy is for countries to strengthen the extraction and utilization of lithium resources, establish long-term lithium resource reserve plans, and improve risk resistance.