There is a great probability in the development of modern urban economy,and the traditional rigid urban planning paradigm can't meet the need of the urban construction.The flexible work method will become the developing direction of urban planning at the new stage.In the flexible urban planning,the items of urban development prediction,land use arrangement,and urban development policies,all have great flexibility and are indeterminate.So the flexible paradigm can keep the urban planning adjustable with the stability in whole.Taking the population prediction of Bengbu as an example,the author finally explains how the flexible method of urban planning works.