Using data from the 2023 China Longitudinal Aging Social Survey ( CLASS ), this study empirically examines the impact of social interaction quality on the health of the elderly by employing the OLogit model and the Conditional Mixed Process (CMP) model. The findings indicate that social interaction quality significantly promotes the health of the elderly, with this effect being more pronounced among female elderly individuals, those with rural household registration, and those with low-to-moderate consumption levels. To address potential endogeneity issues, the Conditional Mixed Process (CMP) estimation method was applied, and the results remained consistent with the benchmark regression. Mechanism analysis reveals that social interaction quality positively affects the health of the elderly by significantly enhancing their sense of role identity, optimism, and life satisfaction. The conclusions of this study provide insights for improving the health of the elderly and promoting active aging.