With the rapid popularity and promotion of Internet in China, the age of people using Internet has been gradually spreading from young group to middle-aged and elderly, and the Internet use has become an integral part of their lives. In order to explore the potential of Internet for the elderly service industry in the future and its impact on the subjective well-being of the future older adults, this study selected 459 Chinese people aged 45–60 as the research object, and adopted the UCLA Loneliness Scale, Subjective Well-Being Scale and Internet use questionnaire to explore the impact of Internet use on subjective well-being of the future elderly in China, using loneliness as a mediation variable. The result shows that: First, the Internet use of future elderly people in China will mainly focus on five aspects including social interaction, entertainment, life service, information acquisition, and personal development. Second, the ability of Internet use degree of elderly people will be significantly affected by some demographic variables include age, occupation, income, and education level while other variables like gender, marital status and housing way do not have significant influences. Last but not least, Internet use will have a significant positive impact on the subjective well-being of future elderly in China, and among them, loneliness will have a complete mediation effect. To sum up, it is concluded that Internet use can significantly promote the subjective well-being of future elderly in China by reducing their loneliness level.