The urban underground commercial space (UCS) in China presents various use states due to different locations, space types, and the construction age of the building, and its commercial space vitality is also different. Commercial space, as an essential part of urban public space, binds the economic activities and social interaction activities of urban life, further its economic vitality and social vitality contribute much to urban vitality. However, there are various factors affecting the vitality of UCS. Considering aspects such as location, connectivity, the functionality of the above-ground part of the building, and nodes of public space, this paper studies the factors affecting the vitality of UCS through on-site investigation and behavioural statistics. Then, we evaluated the results to analyze how various factors affect the vitality of UCS in terms of economic and social vitality. This research could provide references for renovation and reconstruction to enhance the vitality of various existing commercial building spaces, and provide a theoretical basis for the comprehensive planning of UCS.