To quantitatively reveal the impact mechanism of urbanization-induced albedo reduction on extreme precipitation in a single extreme precipitation event, the WRF mesoscale numerical model was coupled with the Noah land surface model and the urban canopy model. With the Beijing’s “23·7” precipitation event as a case study, a comparative analysis was carried out by design of urbanized and non-urbanized albedo through modifying the urban surface albedo parameter, and a sensitivity simulation for 24-h preceding precipitation onset was also conducted. The results indicate that albedo reduction increased the areal average accumulative precipitation by 11% in Beijing, raised the peak hourly areal average precipitation by 28%, and prolonged by 50% of the duration during which the hourly areal average precipitation exceeded 5 mm. The precipitation increase in urban areas and the southwestern mountainous region downwind of the city was the most significant. Albedo changes had already induced initial perturbations in the thermal and humidity fields before precipitation onset. The albedo reduction caused an urban temperature rise of more than 0.2℃, a boundary layer height increase of over 40 m, and a surface pressure decrease of 4 to 8 Pa, thereby enhancing convective motion and convective available potential energy (CAPE). Although CAPE decreased in the southwestern mountainous area, precipitation increased due to the combined effects of urban heat island circulation and topographic uplift. Overall, albedo change induced thermal forcing and its coupling with topographic dynamics exerted a pronounced influence on the spatial distribution of precipitation.