<p>Ethical considerations are of paramount importance in modern disaster management systems, as ethical decision-making directly influences the effectiveness of disaster response and overall social stability. However, existing research has rarely focused on how ethical decisions propagate across multiple levels within the complex disaster management systems and accumulate their effects over time. To address this gap, this paper introduces the concept of <i>ethical cascading failure</i> (ECF) for the first time in academic studies, where a demonstration is made on how ethical misjudgements gradually accumulate, amplify, and ultimately trigger systemic ethical crises in disaster management. This paper proposes that the key characteristics of ethical cascading failure include cumulative effect, uncertainty, systemic impact, chain reactions, and irreversibility. It is pointed out that the influences of such failure are extensive, which extends beyond the immediate disaster response phase, potentially undermining government credit, exacerbating social trust crises, and generating profound long-term implications for governance capacity. It is also proposed that ethical cascading failure is not an incidental phenomenon but rather a consequence of the inherent complexity of disaster management systems interacting with ethical misjudgements. Given its wide-reaching and destructive nature, understanding and mitigating ethical cascading failure is crucial for building a fairer, more resilient, and sustainable disaster governance framework. This study innovatively expands the scope of cascading failures, provides a new analytical tool for ethical assessment in disaster management, and offers academic support for future policy optimisation and ethical risk governance.</p>