<p>Food waste governance is a crucial component in addressing the global food security crisis and achieving sustainable development goals. Three-generation households have been revived against the backdrop of increasing population ageing and corresponding adjustments in population policies. Three-generation households with stronger intergenerational ties exhibit enhanced internal motivations and better external practices in food waste reduction, suggesting a meaningful association with food waste. Based on 2282 research data from six representative cities covering East, Central and West China, this paper examines the association between three-generation households and food waste. The findings reveal that: First, three-generation households are significantly associated with lower household food waste; Second, three-generation households exhibit stronger moral attitudes toward food and higher frequency of home cooking; Third, heterogeneity analysis reveals that the association between three-generation households and food waste varies across food poisoning experience, health status, and income levels. The research advocates for promoting three-generation households and similar intergenerational living models, establishing bidirectional moral attitude transmission mechanisms, promoting home cooking actively in different ways, and implementing subgroup intervention strategies.</p>