Water-saving irrigation technology is essential for agricultural sustainability in arid regions, yet many farmers delay adoption even after recognizing its benefits. Understanding the institutional factors that shorten this adoption lag has important implications for accelerating technology diffusion. This study estimated the effect of Water User Association (WUA) membership on cotton farmers' waiting time to adopt water-saving technology in Xinjiang, China. Using survey data from 1026 farm households, we employed a triple-hurdle model combined with propensity score matching and instrumental variable methods to address potential endogeneity and selection bias. Results indicate that WUA membership is associated with an estimated reduction in waiting time of 0.15-0.27 years (approximately 1.8-3.2 months) and a significant increase in adoption probability. These estimated effects remained robust across multiple estimation strategies. Mediation analysis revealed that approximately 30% of the estimated effect operated through enhanced farmer perceptions, with economic cognition accounting for 15% and social cognition for 10%. Heterogeneity analysis indicated stronger associations among younger farmers, larger-scale operators, and those with technical training. From a policy perspective, these findings suggest that expanding WUA coverage may offer a promising institutional pathway for accelerating technology diffusion in water-scarce agricultural regions, although the generalizability of these results beyond the specific context of Xinjiang's cotton production warrants further verification.