Urban parks aim to improve the living environment and the quality of urban space. However, some urban parks are inefficient in use and lack vitality throughout the day, which leads to thinking about how to effectively improve the quality of urban parks and meet people’s leisure and recreation needs. People and their activities are the main body and external representation of the vitality of urban parks. The real-time and large-scale advantages of mobile signaling data make it possible to quantitatively analyze the behavior characteristics of the urban spatial population and grasp the essence of spatial vitality. Twenty-three urban parks in the central urban area of Suzhou were selected to analyze the temporal and spatial characteristics of the urban park population from the perspective of vitality. Four vitality models are obtained using the time-space analysis method, taking the population size and population density as the direct indicators to measure the vitality of urban parks. With the help of SPSS analysis tools, the correlation between the vitality of urban parks and the influencing factors is analyzed. Finally, it is proposed that the construction of urban parks should focus on the surrounding building crowd and other factors, carry out compound development and pay attention to the park node design to enhance the park vitality in an all-around way.