The digital information era puts forward extremely high requirements for the information literacy of Internet users, while the elderly left-behind people in rural areas, as a vulnerable group in the digital transformation society, are still deep in the digital divide, which is in conflict with the current digital healthy development trend. Based on the root theory, this study conducted in-depth interviews with 30 rural left-behind elderly people from Nanjing, Jiangsu Province, and conducted three-level coding of the interview text, trying to explore the causes and bridging path of the digital dilemma of the rural left-behind elderly in Nanjing. The text analysis shows that the digital divide of the elderly in rural Nanjing is the result of the interaction of multiple factors, in which environmental stimuli play an important role, and cognitive and ability factors play a transmission role. If the status quo remains unchanged, the digital divide will further aggravate the health inequality of the elderly over time. Research found that actively help the old man change ideas, family feedback, social support measures for digital dilemma breakthrough has certain practical significance, should integrate individual, family, social forces, speed up the digital divide, to avoid expanding rural left-behind elderly health inequality, thus boosting digital health construction, the digital dividend benefit the elderly group.