With the widespread use of the Internet among middle-aged and older adults, online safety has become an important issue in the digital era. Using data from the Survey on Digital Division and Inclusion of Older Adults in China, this study reveals that middle-aged and older adults with closer relationships with their children tend to have higher cybersecurity awareness and engage in safer online behaviors. Further analysis reveals that digital knowledge transfer from children and subjective well-being mediate the relationship between intergenerational closeness and older adults' cybersecurity awareness and behaviors. Specifically, a closer intergenerational relationship increases the likelihood of middle-aged and older adults receiving risk-prevention information from their children and leads to higher subjective well-being, thereby enhancing their cybersecurity awareness and promoting safer online behaviors. The findings deepen our understanding of intergenerational relationships as a potential resource in the digital era. Policymakers aiming to improve digital literacy among middle-aged and older adults should consider the role of intergenerational ties and actively involve younger generations, fostering harmonious intergenerational relationships and encouraging “active digital reverse mentoring.”