Sodium-ion batteries (SIBs) have gained significant attention as a promising alternative to lithium-ion batteries(LIBs) due to their cost-effectiveness, abundant raw material resources, and potential applications in large-scale energy storage and electric mobility. However, their commercialization is hindered by performance degradation and failure issues under complex operating conditions. This paper provides a review of the failure analysis of sodium-ion batteries (SIBs), with a particular focus on electrochemical, mechanical, and thermal degradation pathways. The insights gained from this review offer guidance for optimizing electrode materials, refining manufacturing processes, and developing effective operational strategies. Ultimately, these may contribute to improving the reliability of SIBs for practical applications.