The complicated architectural layout and form within urban area lead to the phenomenon of multiple-reflection radiation in the urban area. And this multiple-reflection radiation directly affects the thermal environment in urban areas. This paper is based on the theoretical basis of multiple-reflection between the buildings and converts the problem of urban integrated reflectivity into geometrical parameters which are relevant to the urban spatial structure. At the same time, a case study was taken to obtain an integrated reflectivity which had taken the structure of urban space into account. The results show the integrated reflection is lower 32.4% than the normal situation.