Abstract: to examine the impact of policy on the livelihood resilience of border-area farmers and to uncover the underlying mechanisms, this study draws on valid survey data from 589 households in Yunnan’ s border regions. Based on the sustainable livelihood analysis framework, we construct a six-dimensional livelihood resilience evaluation system encompassing human capital, natural capital, physical capital, financial capital, social capital, and psychological capital. The entropy weighting method is employed to determine the relative importance of each dimension and calculate a composite resilience index, while a structural equation model (SEM) is applied to reveal the pathways through which the “Prosperity for Border Areas” policy influences farmers’ livelihood resilience. The results show that: (1) the overall level of livelihood resilience is low, with most indices ranging between 0–0.35, an average value of 0.2045, and a maximum of 0.6480; (2) policy perception exerts a significant positive effect on livelihood resilience (path coefficient = 0.62), and participatory behavior also plays a substantial role (0.53), whereas participatory awareness has a relatively limited impact (0.10); (3) the policy mechanism primarily operates through a synergistic effect generated by enhancing farmers’ policy perception and their level of behavioral participation, thereby strengthening livelihood resilience. Based on these findings, targeted strategies are proposed in three areas—optimizing livelihood capital structures, improving policy support systems, and stimulating farmers’ agency—to promote resilient rural development in border areas and provide theoretical and practical guidance for the effective implementation of the “Prosperity for Border Areas” strategy.