Based on the grounded theory，this study conducted in-depth interviews with 30 rural left-behind older adults from Nanjing，Jiangsu Province，and conducted three levels of coding of the interview text to explore the causes and bridging path of the digital dilemma of the rural left-behind older adults in Nanjing. The text analysis showed that the digital divide among rural left -behind older adults results from the interaction of multiple factors，in which environmental stimuli play an essential role，with cognitive and ability factors playing a transmissive effect. If the status quo remains unchanged，the digital divide will further aggravate the health inequality among older adults. A variety of measures including integrating individual，family，and social forces， actively helping older adults change attitudes，strengthening family feedback，relying on social supports，etc. should be taken to break through digital dilemma and promote digital health construction，so that the digital dividend benefits the vast number of elderly populations.