Background <p>Against the current backdrop of low fertility and high internal migration in China, the traditional living arrangement in which widowed older adults co‑reside with adult children has become increasingly constrained. Many older adults now live alone following spousal loss. Existing studies have typically examined the consequences of widowhood in isolation or described the advantages and disadvantages of living alone in static terms, without integrating both dimensions into a dynamic, person‑centered framework of psychological adaptation. Therefore, situated within the sociocultural context of southwestern China, this study aimed to explore the dynamic relationship between vulnerability and agency among this population.</p> Methods <p>This study employed a qualitative descriptive design. Semi‑structured in‑depth interviews were conducted individually with 16 widowed older adults living alone between September and December 2023. The data were analyzed using thematic analysis.</p> Results <p>Two overarching themes emerged from the data analysis: “inner dilemmas” and “adaptive self‑reinvention”. The theme of inner dilemmas comprised four subthemes: constrained agency, unspoken sorrow, digital alienation, and remarriage ambivalence. Adaptive self‑reinvention included four corresponding subthemes: proactive planning, peer interaction, digital adaptation, and meaning reconstruction.</p> Conclusion <p>The core experience of widowed older adults living alone reflects a dynamic relationship between vulnerability and agency. Within this tension, they navigate persistent inner dilemmas while simultaneously engaging in a process of adaptive self‑reinvention. This reinvention does not signify the elimination of dilemmas, but represents a continuous effort to preserve autonomy and sustain meaning in later life. Therefore, it is essential to foster supportive social environments that alleviate psychological burdens while also encouraging the use of proactive, adaptive coping strategies in this population.</p>