The lifting of COVID-19 restrictions has brought about positive changes, yet the adaptation of the elderly in the post-pandemic era still faces challenges. The purpose of this study is to investigate the health changes in the elderly after the lifting of COVID-19 restrictions through a quasi-natural Experiment design, to unravel the effects of the lifting of the pandemic restrictions. The article is based on the data of the elderly in China and South Korea from 2020 to 2022 and employs the PSM-DID method for empirical testing to examine the impact of the lifting of pandemic restrictions on the health of the elderly. The results show that: (1) The lifting of the pandemic restrictions significantly improved the physical health of the elderly. (2) The lifting of the pandemic restrictions effectively improved the mental health of the elderly and significantly reduced their depression scores. (3) Heterogeneity tests indicate that the lifting of the pandemic restrictions had a more treatment effect on improving the health of elderly groups that are female, younger, lower-income, and suffering from chronic diseases. The gradual recovery of health in the elderly in the post-pandemic era is an important phenomenon, but more research is needed on the potential health impacts of pandemic lockdown measures to provide information for the fields of public health and elderly health.