<p>This study delves into the complex relationship between intergenerational support and the subjective well-being of the elderly against the backdrop of an aging population. Using data from the 2020 China Family Panel Studies, we explore the correlation between intergenerational support and the subjective well-being of older adults across three dimensions: financial, instrumental, and emotional. The study further reveals the pathways through which intergenerational support affects the well-being of the elderly and the potential factors influencing this relationship. The findings indicate a significant positive correlation between various forms of intergenerational support and the subjective well-being of older adults, with financial support having the most pronounced effect, followed by emotional and instrumental support. Through mediation analysis, we discover that intergenerational support positively correlates with the self-efficacy of the elderly, thereby enhancing their subjective well-being. Lastly, from the perspective of filial piety culture, we examine how expectations of filial piety serve as a moderating variable, influencing the relationship between intergenerational support and the subjective well-being of the elderly. In cultural contexts with low expectations of filial piety, financial support shows a significant positive correlation with the well-being of the elderly; conversely, in contexts with high expectations, emotional support plays a more crucial role in affecting well-being. This study not only enriches our understanding of the relationship between well-being and family support in the aging process but also provides valuable insights for formulating and implementing family-centered policies aimed at enhancing the well-being of older adults.</p>