Global climate change and accelerated urbanization have led to increased frequency of extreme rainfall events, significantly elevating urban flood risks. Conventional minor drainage systems, which predominantly rely on pipeline networks, demonstrate considerable limitations under extreme rainfall conditions. In contrast, major drainage systems (MDS) with integrated storage and drainage functions are increasingly recognized as a crucial approach for enhancing urban flood resilience. This article provides a systematic review of recent research developments in this domain, focusing specifically on optimized design methodologies for stormwater detention tanks and road-based MDS. Key aspects addressed include optimal layout of storage facilities, development of multi-functional storage spaces, risk assessment of road drainage systems, and the application of intelligent optimization algorithms. Results indicate that data-driven intelligent optimization and real-time control (RTC) are transcending the constraints of traditional empirically based design approaches, facilitating the transition of urban drainage systems toward smarter, more adaptive, and coordinated operations. Finally, the study outlines future research directions, including enhanced RTC strategies, generalization of cross-scenario optimization frameworks, and improved synergy between storage and drainage infrastructure. These insights aim to offer theoretical and technical references for developing advanced urban MDS capable of addressing challenges posed by extreme rainfall.