[Objective] By integrating rural flash flood resilience and ecosystem regulation services into a unified framework, the spatiotemporal evolution patterns of their coupling and coordination relationship were investigated in order to provide support for the sustainable development and decision-making for disaster prevention and mitigation in mountainous rural areas [Methods] Focusing on southwestern Sichuan Province, a region characterized by high flash flood incidence and strategic ecological importance, the pressure-state-response(PSR) model was used to construct a rural flash flood resilience assessment system. The revised universal soil loss equation(RUSLE) and the water balance equation were used to quantify soil conservation and water yield services, respectively. The coupling coordination degree model was utilized to quantitatively evaluate the coordination relationship between the two systems. [Results]① From 2013 to 2023, rural flash flood resilience level rose from 0.343 to 0.471, showing a stable spatial pattern of ‘ high in the north and low in the south '.② Ecosystem regulation services matched the hydrothermal patterns, but were influenced by climate fluctuations, exhibiting non-linear changes with distinct regional differentiation.③ The coupling coordination relationship demonstrated pronounced functional differentiation and spatial polarization. Rural flash flood resilience showed better coordination with soil conservation. However, its coordination with water conservation exhibited sharp polarization, with most northern areas in a state of ‘high-quality coordination', whereas the hinterland of Liangshan in the south remained in a state of ‘moderate dysfunction' or even ‘severe dysfunction' for a long time. The enhancement of water conservation was constrained by more stringent natural background conditions, frequently resulting in a bottleneck effect. [Conclusion] Future strategies for enhancing rural flash flood resilience should avoid a ‘one-size-fits-all' approach. For the northern coordinated areas, efforts should focus on improving efficiency and quality. For the southern dysfunctional areas, emphasis should be placed on addressing weaknesses and promoting flood-adaptive restoration. Specifically, combining drought-tolerant vegetation with slope-to-terrace conversion should be promoted to achieve the coordinated development of the human-water-soil system.