Developing rural elderly-caring services on the premise of stimulating the endogenous driving force of rural areas not only makes up for the deficiency of existing studies that focus on identifying “where the shortcomings of rural elderly-caring services lie” and “how to address these shortcomings”—a focus that has led to the neglect of rural areas’ subjectivity—but also conforms to the policy shift in the supply of rural elderly-caring services during the 15th Five-Year Plan period, from emphasizing “addressing shortcomings” to taking into account “sustainability”. Based on on-site field investigations of two case villages in Ordos City, and by constructing an analytical framework from the perspective of the need spillover theory, this paper explores the practical form, operation mechanism, and impacts of building a governance community for a rural aging society supported by the collective economy. The findings are as follows. First, taking the need spillover theory as the basic theory for analyzing rural elderly-caring issues has strong applicability and explanatory power. Second, by implementing the “land-based elderly care” model and the “aging-in-place” model, respectively, the two case villages have achieved a developmental shift in the practical form of elderly-caring services from the “supply-demand mismatch type” to the “supply-demand adaptive matching type”. Finally, under the analytical strategy of placing land at the core of the rural aging social form, building a governance community for rural aging society supported by collective economy involves a dual operational mechanism: on one hand, the “productive” and “welfare” attributes of land are the guarantee of enhancing the supply capacity of rural public services and forming geographical solidarity, thereby promoting the formation of “community of interests” and “community of life”, which has brought abundant “governance resources” to rural aging society; on the other hand, the “cultural” and “political” attributes of land have activated the collective identity of the public attribute of elderly caring and given rise to a new order of rural governance featuring joint construction, joint governance, and shared benefits, and shaped “community of emotion” and “community of organization”, aiming to achieve high-level “governance efficacy” in rural elderly society.