Consolidating and expanding the achievements of poverty alleviation, and effectively connecting it with rural revitalization, are part of an important path to achieving sustainable poverty alleviation and common prosperity in China, especially in its northwest arid areas. In this paper, the human–earth system was employed to analyze the elemental composition, structural organization, and functional state of China’s northwest arid areas. The results revealed the following: (1) poverty in northwest arid areas stems from the lack of a coupling and coordinating mechanism among humans, the economy, resources, and environmental elements; this is not conducive to transforming ecological advantages into regional development. (2) In the antipoverty stage, China’s northwest arid areas innovate human–earth coupling and a coordinating mechanism through a series of targeted measures. (3) We found that three paths, namely “promoting the integration of featured advantageous industries and tourism culture, innovating the realization path according to local conditions, and paying attention to the subjectivity of farmers” broaden the means of sustainable livelihood, consolidate the achievements of poverty alleviation, and achieve rural revitalization. (4) In particular, it is necessary to practice the concept of green development and pursue ecological industrialization by establishing a policy system of green land-people-industry-right, thus building an endogenous growth mechanism of sustainable poverty alleviation and green development in China’s northwest arid areas. The results provide theoretical support and model reference for the effective connection between consolidating and expanding the key achievements of poverty alleviation and rural revitalization in China’s northwest arid areas.