在快速城市化与气候变化叠加背景下，极端降雨强度增强加剧城市内涝风险，传统排水系统面临超负荷运行压力。针对未来降雨情景下雨洪调控能力不足问题，构建集成CMIP6多模式预测、SWMM水动力模拟与XGBoost-NSGA-Ⅲ耦合优化的灰绿基础设施配置优化框架，分析不同投资水平下设施配置结构演化规律。以北京市凉水河流域大红门地区为例，基于泰勒图与年际变率得分筛选优势模式并构建加权集合情景，开展多目标优化。结果表明：多模式加权提升历史降雨模拟能力，未来极端降雨显著增强，SSP585情景下10 a一遇降雨量超过历史50 a一遇水平；优化可有效降低径流与溢流风险，但排放增强时所需投资上升；设施结构由集中式灰色调蓄向分布式绿色调控转变，绿色设施由透水铺装主导逐步转向绿色屋顶。研究成果可为未来气候变化背景下城市雨洪适应性规划提供方法参考。

[Objective] Conventional grey pipe-network-dominated drainage systems exhibit limited adaptability when confronted with beyond-design storm events. Existing optimization studies of green-grey infrastructure are predominantly conducted under historical rainfall conditions and insufficiently account for future climate change scenarios and their associated uncertainties，particularly with respect to the systematic selection and integration of multiple climate models. To address these gaps，this study constructs a multi-objective optimization framework coupling an XGBoost surrogate model with the NSGA-III algorithm，driven by CMIP6 multi-model climate projections. [Methods] Dahongmen Area in the Liangshui River Basin of Beijing was taken as a case study. We first evaluated eight CMIP6 global climate models （GCMs） that have shown relatively strong performance in northern China. Using historical rainfall observations from 1982-2014 as the benchmark，spatial downscaling was conducted via linear interpolation，followed by bias correction using the Delta method. A comprehensive assessment framework was then established by integrating the Taylor Score （TS） and the Interannual Variability Score （IVS）. Based on this framework，three models—EC-Earth3，ACCESS-CM2，and IPSL-CM6A-LR—were identified as the best-performing candidates. These selected models were subsequently combined using a weighted ensemble approach to construct future rainfall sequences under SSP1-2.6，SSP2-4.5，and SSP5-8.5. Second，to improve computational efficiency for optimization，an XGBoost （XGB） surrogate model was developed to characterize the nonlinear response relationships among rainfall characteristics，the deployment scale of green-grey infrastructure，and the resulting total runoff and cumulative overflow. Finally，with the minimization of annualized cost，total runoff，and total overflow as the objective functions，the XGBoost was coupled with the NSGA-III algorithm for multi-objective optimization. This produced Pareto-optimal solution sets under each scenario. Representative designs—including cost-optimal，compromise，and benefit-optimal solutions—were then selected to systematically analyze the configuration structure and evolutionary patterns of green-grey infrastructure across varying investment levels. [Conclusions] （1） EC-Earth3，ACCESS-CM2，and IPSL-CM6A-LR show relatively good performance in precipitation simulation for the Dahongmen area of Beijing. Compared with single models，the weighted multi-model ensemble improves the simulation accuracy of historical precipitation and reduces the uncertainty caused by biases of individual models. （2） Under different future emission scenarios，extreme rainfall intensity shows an overall increasing trend. Under the SSP5-8.5 scenario，the 10-year return-period rainfall exceeds the historical 50-year level，and the 100-year return-period rainfall intensity increases by 43.9%，indicating a higher risk of exceedance for urban drainage systems. （3） Optimization of green-grey infrastructure effectively reduces runoff and overflow risks. Under the low-emission scenario （SSP1-2.6），overflow can be completely controlled. Under the high-emission scenario （SSP5-8.5），a certain overflow risk still exists even at high investment levels，and the investment cost required to achieve the same control target increases with the intensification of emission scenarios. （4） The allocation of green-grey infrastructure presents obvious staged evolutionary characteristics. In the early stage of optimization，centralized grey detention facilities are dominant，which enhances the basic regulation capacity of the drainage system. With increasing investment，the optimization strategy gradually shifts toward distributed green infrastructure. Within green infrastructure measures，the priority changes from permeable pavement to green roofs，reflecting a structural transition from centralized detention to source control. This study reveals the adaptive evolution mechanism of urban green-grey infrastructure configuration under climate change，and provides a scientific basis and technical support for the phased construction and investment decision-making of urban drainage systems under intensified extreme rainfall conditions.