基于海绵城市建设理念，针对现阶段建筑小区尺度上灰-绿结合海绵设施缺乏科学配置与布局优化的问题，以宜昌市某建筑小区为研究对象，构建精细化的城市雨洪模型与以经济效益和水文效益为导向的优化算法，对研究区灰-绿海绵设施进行多目标优化，得出灰-绿海绵设施空间布局优化方案。该优化方案与研究区规划方案相比，成本提高20.46%，但溢流控制量和径流控制率分别提升了28.30%和25.82%；与可布设的最大灰-绿海绵设施方案相比，成本降低了17.97%，而溢流控制量和径流控制率分别降低了10.99%和3.36%，并在30年一遇长历时暴雨情景下实现小区底层住户不进水。优化方案有着良好的经济与水文效益，研究成果可提高海绵城市设施布局的科学性与合理性，为缓解现阶段同类城市面临的内涝难题，推动海绵城市建设从试点走向示范提供一定技术支撑。

The acceleration of urbanization has changed the characteristics of the original underlying surface, destroyed the previously stable water circulation system in nature, and intensified the probability of urban flood disaster. In recent years, the concept of sponge city construction is continuously being developed, and the concept of "blue, green and gray" infrastructure has been proposed, which possibly could reduce the risk of urban flooding. In the process of sponge city construction, the sponge transformation of building districts is an important content. However, the recent research at this stage focuses on a single green or gray facility layout, and few scholars have conducted research on the scientific allocation and layout optimization of gray-green combined sponge facilities on the scale of building districts. The current research on sponge infrastructure should align with the specific requirements of regional sponge city construction. Therefore, a building district in Yichang City was selected as the research area. The urban storm flood model combined with the optimization algorithm model, a multi-objective optimization was carried out to optimize the deployment ratio of sponge infrastructure, and the scheme with the highest score was compared with the current situation of the study area and the scheme with the maximum allowed deployment of sponge facilities. Compared with the study area planning scheme, the cost of the optimization scheme was increased by 20.46%, but the overflow control volume and runoff control rates were also increased by 28.30% and 25.82%, respectively. Compared with the largest gray-green sponge facility that can be deployed, the cost showed a reduction of 17.97%, while the overflow control volume and runoff control rate were reduced by 10.99% and 3.36%, respectively, and the bottom residents of the community were not flooded under the scenario of a long-lasting rainstorm once in 30 years. The optimization scheme proposed illustrate the economic and hydrological benefits. The research showed that: (1)When the scale of various grey and green sponge facilities was increased, the range of runoff and overflow reduction control moved gradually towards stability, this means that in the process of sponge city construction, the growth rate of sponge facilities for flood response control will gradually slow down with the increase of their investment scale (2) The optimized sponge construction scheme reveals economic and hydrological benefits, and can provide technical support for future sponge city constructions.