Ageing is accompanied by changes in brain intrinsic functional connectivity (FC) and cognitive decline. Although the connection between resilience and cognitive performance in older adults has been explored, the neural mechanisms underlying this relationship remain elusive. Processing speed is vital for daily functioning and independence among older adults Specifically, how resilience impacts intrinsic FC within brain networks and individuals' processing speed has yet to be thoroughly addressed. To uncover this question, we recruited 102 healthy ageing individuals aged 60-79 to complete a resting-state functional magnetic resonance imaging (fMRI) scanning. We assessed their resilience by score of The Chinese version of the Dispositional Resilience Scale (DRS-15) and processing speed using the well-characterized test: the Symbol Digit Modalities Test (SDMT). We then calculated the degree centrality to represent the intrinsic FC between caudate and other brain regions. Partial Spearman correlation analyses, controlling for age, sex, and years of education, revealed significant negative correlations between caudate degree centrality and both processing speed (rho = 0.31, p = 0.002) and resilience (rho = 0.28, p = 0.005) in older adults. Moreover, a mediation analysis demonstrated that caudate degree centrality fully mediated the association between resilience and processing speed in older adults (indirect estimate = 0.13, p < 0.05, 95% CI = [0.03, 0.28]). Our findings suggest that intrinsic FC in caudate plays a crucial role in information processing speed in older adults and highlights the protective role of resilience in preserving cognitive function during ageing.