This paper selects the evaluation index system of sustainable development for reliability analysis from urban traffic system internal problems, city traffic sustainable development on the consumption of resourcesutilization. Based on PCA-DEA model, it makes the reliability analysis of the sustainable developmentof urban traffic with the relative data from 2006 to 2011 to show:（1）the whole efficiency slope up withthe optimization of the infrastructure construction and the traffic management system during 2006 to 2008 inBeijing.（2）Technology efficiency did good running in the year of 2006,2009,2010, which shows the distribution efficiency for the infrastructure construction of Beijing.（3）It is problems of scale that restrict the sustainable efficiency of the transportation of Beijing, but not the distribution efficiency, with the influence factors considered. It means that the emphasis of the sustainable development of Beijing traffic would be still the enlargement of investment of traffic infrastructure construction and the improvement of bearing capacity.