Abstract: As smart devices gradually enter households, they play an increasingly vital role in the lives of older adults, proving crucial for enhancing their health. This study utilizes data from the 2018, 2020, and 2023 CLASS surveys and employs a multi-wave DID analysis method to examine the relationship between smart device usage and older adults’ health. Findings reveal: First, using smart devices has a significant positive effect on older adults’ health levels; Second, the health benefits of smart devices vary by device type: health management devices yield the most pronounced benefits, while assistive living devices are effective only for certain elderly populations, and monitoring devices show no significant health benefits. Third, the health benefits of smart device usage exhibit population heterogeneity: effects are more pronounced among healthy seniors but negligible for those with basic functional limitations. Compared to urban seniors, rural seniors demonstrate more pronounced benefits from smart device usage.