One of the characters of urbanization is that cities develop spatially. The harmful effects of urban heat island put a burden on environmental preservation, energy saving, and thermal comfort. High-albedo materials can lower temperatures effectively when exposed to solar radiation. According to the albedo change of the wall-facing materials of urban buildings, two building models were constructed, of which the internal and external microclimate parameters were measured under certain meteorological conditions in summer. The analytical results of the internal heat environments show that employing high-albedo coatings on the building exterior wall was an active and effective approach to mitigating the high temperatures in the urban environment and its consequences. Moreover, an integral method was used to calculate albedo, which supplies an effective way in the selection of coatings, the performance analysis of the heat insulation, and the assessment of the building microheat environment.