In the social context of population aging and digitization, the rural elderly face a more prominent digital divide due to the reality of urban-rural dual structure. Bridging this gap has become an urgent problem that needs to be addressed. This paper constructs a theoretical framework of "individual action-social structure-duality of structure" based on structural theory to analyze the formation mechanism of the digital divide among rural elderly. The study finds that this divide is caused by routinization and regionalization in their actions, loss of social resources, and absence of rules, which interact with each other. Therefore, bridging this gap requires intervention at multiple levels including rural elderly individuals, digital society as well as their interaction; constructing a more reasonable structural relationship can help bridge this digital divide.