The design of subway information spaces is highly complicated and multifaceted, lacking theoretical guidance. To address this issue, this study proposes a design approach for subway information spaces based on field theory. Taking the subway information space as the object of study, it analyzes the human-machine-environment interaction within the space using field theory. Drawing on the research of scholars Stan Allen and Wang Xingyu, this study introduces the concept of a gravitational field and explains the information interaction mechanisms within the field through the three elements of capital, habitus, and symbols. Based on the relationship between the subway information field and the gravitational field, a planning and design approach for subway information spaces from the perspective of the gravitational field is presented in this study. A case study on the design improvements of the interactive digital media community at Jianghan Road Subway Station, Wuhan, Hubei Province, China, demonstrates how to apply these design strategies. This research seeks to enhance the efficiency of subway information spaces, improve passenger experience, and provide theoretical guidance and practical references for the sustainable development of subway systems.