The research proposes a method for spatial distribution analysis of urban population in the central urban area of Chongqing city, aiming to formulate scientific and rational schemes for population dispersion. This method is based on the built environment and involves the following steps: firstly, acquiring built environment variables using multi-source geographical data; secondly, calculating the grey correlation between built environment variables and residential population, thereby filtering strongly correlated variables; and finally, training a random forest model on the selected variables to construct a spatial model of residential population distribution. The results indicate that this method achieves a high fitting accuracy for residential population spatialization, effectively to simulate urban residential population distribution and accurately understand the spatial distribution of residential population.