Abstract: Land-bridge islands isolated from land typically evolve into a complete and unique ecosystem. Despite their unique value in global biodiversity protection, land-bridge islands are poorly protected nowadays. Current biodiversity researches mostly focus on macro-scale concept and strategy, and seldom pay attention to research, analysis and practical experience on biodiversity improvement in island ecosystem. Taking the ecological restoration of Guangyang Island as an example, this research deeply analyzes the biodiversity characteristics of and biodiversity challenges faced by the ecosystem of land-bridge islands, and puts forward the following six strategies: 1) identify critical habitats with a focus on key patches and corridors;2) remove invasive specie to restore system balance; 3) protect rare species to restore habitats; 4) introduce suitable species to improve the complexity and stability of the food chain;5) formulate control guidelines to reduce human intervention; 6) establish a monitoring system to achieve dynamic protection. This research can provide reference for biodiversity protection research and practice in similar regions.