The rapid development of modern society has led to more and more pressure on the public, which has seriously affected the public’s health. The subway station is a transit space for public travel. Although the stay time is not long, it can also take a short rest and relaxation through a small indoor park to promote mental recovery. In this regard, this paper will explore the value of natural elements in the application of small indoor parks in subway stations, and put forward suggestions for the design of small indoor parks in the future. The scope of this study is to select the small indoor Park of subway station with clear theme in Seoul as the research object. By sorting out relevant theories, establish a connection between the characteristics of natural elements and the corresponding points that can show value, draw a checklist and conduct field investigation, and analyze the specific value of natural elements in indoor small parks. Through case analysis, it is concluded that breaking the sense of indoor blockade is the greatest value of the application of natural elements in indoor small parks, and the wide field of vision and the introduction of natural light play a great role. Secondly, the rich forms of natural elements and appropriate scales can promote the public to shift their attention to the environment, and the relaxed state can promote the relief of pressure. Finally, the rich natural elements in the indoor small park provide users with opportunities to contact a variety of natural environments, which will better promote a healthy life.