Abstract: The Guangdong-Hong Kong-Macao Greater Bay Area (GBA) is one of China’s most economically dynamic and highly urbanized coastal regions. It hosts extensive mangrove ecosystems whose conservation and restoration are critical for regional sustainable development. This study employs a mangrove assessment indicator system grounded in IPCC climate risk theory by integrating multi-source data (literature, remote sensing imagery, and model simulations). It systematically evaluates the spatiotemporal evolution of climate risks for GBA mangroves through 2030, 2050, and 2100 under different Representative Concentration Pathways (RCPs) scenarios (RCP2.6, RCP4.5, RCP8.5) for low, medium, and high greenhouse gas emissions, respectively. Climate adaptation strategies are also proposed. The results indicate: ① Compound hazard induced by delayed sea level rise (SLR) and sudden tropical cyclones (TCs) events will continuously intensify across all RCP scenarios. Under RCP4.5 and RCP8.5 scenarios, the tracks of strong TCs making landfall in China will shift significantly northward, leading to a slowing growth rate of TC hazard in the GBA. Meanwhile, the contribution of SLR to hazard will far exceed that of TCs. ② The exposure level of mangroves, from high to low, is as follows: Qi’ao-Dangan Island Provincial Nature Reserve, Neilingding Island-Futian National Nature Reserve, and Zhenhai Bay. While the vulnerability level of mangroves from high to low is: Zhenhai Bay, Neilingding Island-Futian National Nature Reserve, and Qi’ao-Dangan Island Provincial Nature Reserve. ③ By 2100, the proportion of mangrove area at very high risk under the RCP scenarios shows significant gradient differences, e.g. 0.28% (RCP2.6)＜6.76% (RCP4.5)＜57.42% (RCP8.5) with the Qi’ao-Dangan Island Provincial Nature Reserve having the highest risk. The analysis shows that implementing adaptation measures such as bio-shoreline protection, sediment regulation, and replanting of native species can effectively enhance the scientific management of climate risks and improve the climate resilience of high-risk mangrove systems.