Urban residential planning focuses on location, environment, house type and public facility, etc. The efficiency of disaster prevention system, a part of invisible public benefit, is lack of full attention except basic requirements. Based on the classification of urban residential safe space mode, we propose the factor hierarchy of urban residential safe space based on comprehensive disasters prevention. We firstly divide the stages of disaster prevention into two stages as prevention and emergency. Then we classify the spatial elements related to different kinds of disasters and implement them on the macroscopically, middle and microscopic special levels. Finally, we build up the factor hierarchy through classifying and integrating the elements.