Due to the rapid development of cities and the intensification of human activities, anthropogenic heat emissions play an important role in the impact of urban thermal environment, which is an important factor in causing the urban heat island effect. Analyzing the spatiotemporal distribution characteristics of anthropogenic heat is of great significance for achieving sustainable urban development. The anthropogenic heat flux is divided into four categories of heat flux emissions based on energy type: industry, transportation, building, and metabolism, and anthropogenic heat flux data are calculated for each province in China from 2000 to 2020. The fitted equations for nighttime lighting data and anthropogenic heat fluxes were then constructed through a Geographically and Temporally Weighted Regression (GTWR) model. The spatial distribution of anthropogenic heat fluxes at 500 m resolution were simulated for 2000-2020 in China. The results show that from a spatial perspective, the anthropogenic heat flux in the eastern coastal area is the highest, and the anthropogenic heat flux shows a downward trend from the eastern region to the central and western regions. The high growth type and high level of anthropogenic heat flux are mainly distributed in the eastern region, while the low growth type and low level of anthropogenic heat flux are mainly distributed in the western region. Among the eight major urban agglomerations, Shanghai-Nanjing-Hangzhou and the Pearl River Delta have the most significant growth in anthropogenic heat flux, with the highest proportion of high-level heat flux. In terms of time, the anthropogenic heat flux in China increased from 0.924 W/m2 in 2000 to 1.783 W/m2 in 2020, with an annual growth rate of 4.56%. The anthropogenic heat flux emissions are showing an increasing trend.