Abstract: Exposure to the natural environment contributes to relieving anxiety. However, during the regular prevention and control of COVID-19 pandemic, the nearby natural environment of the middle-aged and elderly people may have a different influence mechanism on the anxiety. This research aims to examine whether exposure to various types of nearby natural environments could alleviate the anxiety induced by the pandemic among the middle-aged and elderly people. It reviews relevant theories, constructs the analysis framework, investigates related features among the middle-aged and elderly people, such as nearby natural environment exposure, pandemic stress, and anxiety, and carries out regression analysis on the survey data. The environmental quality and exposure intensity of the community green space, and the exposure intensity of home ornamental plants do not show significant moderating effect on the relationship between pandemic stress and anxiety, which suggests they cannot relieve the anxiety induced by the COVID-19 pandemic stress. The area of home ornamental plants shows significant moderating effect on the relationship between pandemic stress and anxiety, which suggests that engaging in home gardening can relieve the anxiety induced by the COVID-19 pandemic stress. The positive effect of COVID-19 pandemic stress on anxiety is relatively lower when the area of home ornamental plants is large. This research deepens the discussion of the mechanism in which different types of nearby natural environments affect mental health in the context of COVID-19 pandemic, and provides solutions to effectively alleviate public anxiety during the COVID-19 pandemic.