Passive daytime radiative cooling (PDRC) enables electricity−free heat dissipation through the atmospheric transparency window, yet conventional static spectral designs struggle to adapt to diverse climatic conditions and application demands. This review systematically examines the recent progress in multifunctional coupling strategies for PDRC across three key directions: intelligent thermal management, energy harvesting, and integration with emerging functionalities. In the realm of intelligent thermal management, we summarize passive mechanisms responsive to temperature and humidity, as well as active regulation via mechanical and electrical stimuli, highlighting the transition from continuous cooling to on−demand thermal control. Regarding energy harvesting, we analyze synergistic approaches combining PDRC with thermoelectric generators, triboelectric nanogenerators, and atmospheric water harvesting, revealing the mechanisms that enable integrated cooling, power generation, and water collection. For emerging functionalities, we introduce coupling schemes involving photoluminescence, sensing, and structural color design, illustrating innovative solutions that resolve the inherent trade−off between coloration and cooling performance while expanding application boundaries. Based on these analyses, we identify common challenges in current research, including trade−offs in material performance, long−term stability, system integration complexity, economic feasibility, and environmental adaptability. Future efforts should focus on the synergistic design of stimuli−responsive materials and efficient energy conversion structures, establish performance evaluation frameworks under diverse service conditions, and promote the evolution of multifunctional coupled radiative cooling technologies toward adaptive, scalable, and multi−energy complementary intelligent platforms.