In 2020,the decisive victory of building a moderately well-off society in all aspects means that absolute poverty in rural China has been completely eliminated.Consolidating and expanding the achievements of poverty alleviation and establishing a long-term mecha-nism to solve relative poverty have become key issues in high-quality development of un-derdeveloped areas.In this study,human-earth system is employed to analyze the element composition,structural organization and functional state of underdeveloped areas.The re-sults show that poverty in underdeveloped areas stems from the lack of the coupling and coordinating mechanism among human,economic,resource and environmental elements,which is not conducive to transforming the ecological advantages into the advantages of re-gional development.In the antipoverty stage,underdeveloped areas innovate the hu-man-earth coupling and coordinating mechanism through a series of targeted measures,promote the organic combination of poverty alleviation,ecological conservation and sus-tainable development,and boost the transformation of regional development and the increase of farmers'incomes.Focusing on the 14th Five-year Plan(2021-2025)and the long-term goal of 2035,governments in underdeveloped areas should make full use of the policy sup-port to explore scientific methods of modern governance and sustainable development.In particular,it is necessary to practice the concept that"clear waters and lush mountains are invaluable assets"and take the road of the ecologicalization of industry and the industrializa-tion of ecology by establishing a policy system of"green land","green people","green indus-try"and"green right",thus building an endogenous growth mechanism of sustainable poverty alleviation and green development in China's underdeveloped areas.