With the development and application of LAD and LBS, the digital footprint of the user has provided convenience for effectively displaying the trajectory of urban population flow and the spatio-temporal aggregation, which makes up for the shortcomings of traditional urban research and spatial planning. With the help of Baidu heat map and ArcGIS, this paper analyzes the temporal-spatial footprint of population flow of the central city of Wuhan City. The results showed that: the population agglomeration showed obvious fluctuation, but the fluctuation of working days was stronger than that of the rest days, and the activity track was highly consistent with the commuting rhythm, while the rest day was more stable. There is a phase difference between working days and rest days; the time of population flow and accumulation is earlier than the rest; the afternoon, the day of rest, the time of population flow and focus lag behind the working days. Whether on weekdays or on the day off, the concentration of the morning is low, and the concentration of people in the afternoon and evening is higher, and is much higher than that in the morning. In the spatial footprint, the working day and the rest day are gathering together the spatial position approximately same, the working day mainly is the commercial center, the transportation hub and the employment center, displays the very obvious work direction. Days off point to traditional shopping centre, large transportation hubs and emerging urban complexes.