Research on high-resolution population evolution is of great reference for understanding, simulating, and managing the human-nature interrelationship. Town-level demographic data is the highest-resolution data publicly released by the National Bureau of Statistics of China. Therefore, it is of great significance to collect the population data of China at town level, and to carry out research on the spatiotemporal evolution and its influencing factors of Chinese population at town level. In this study, we established a spatial database of Chinese population at town level in 2010 and 2015, and then revealed its spatial and temporal pattern and influencing factors by Geographic Information System (GIS) analytical methods and Geodetector model. The results showed that: (1) In 2015, the average population of towns was 29,500, and the average population density was 374 persons/km2. Furthermore, there existed large spatial heterogeneity in China, the number of townships with a population of more than 10,000 is 781, mainly in the Yangtze River Delta and the Pearl River Delta, while the number of townships with a population of less than 5,000 is 2,498, mainly in the Qinghai-Tibet Plateau and Inner Mongolia. (2) The distribution of population and land area of townships was greatly uneven. There were 19,403 (60.81%) townships with a population density of more than 150 persons/km2, and their total population and land area accounted for 81.76% and 20.27%, respectively, which was approximately in line with “Pareto's Law”. (3) From 2010 to 2015, more than 70% towns’ population increased, by contrast, the population of more than 9,000 towns decreased, of which more than 1,600 towns experienced a population loss of more than 20%, and most of them were located in the border areas of Northeast China, Inner Mongolia and Yunnan. (4) The population distribution is comprehensively affected by physical geography (e.g., relief degree of land surface, negative effect) and socio-economic factors (e.g., night time light index and road density, positive effect), and its mechanism has obvious spatial stratified heterogeneity in different regions. This study argues that the rapid population growth or loss brings great challenges for harmonizing human-environment relationships, such as territory spatial planning, rural revitalization and national border security.