Crises became natural in cities during the twenty-first century, due to climate change, economic and social, as cities face many urban problems, cities do not predict upcoming problems but can plan to address them, that is, achieving flexibility with willingness and ability to adopt alternative strategies such as responding to changing conditions and crises Sudden, positive adaptation and shift to sustainability, through more flexible systems and alternative ways of using resources in times of crisis, as cities are subject to flexible and sustainable urban design in preparation for a number of issues (urban, social, Economic and environmental) according to a sustainable future vision, and the research aims to apply theories of sustainability and flexibility in urban design for cities to manage and operate urban societies, through environmentally friendly principles so that they are flexible in design and in order to ensure sustainable urban design to provide the needs of cities with water, electricity and food for all its parts, and to achieve Principles of zero-frame sustainability, by designing with nature and linking the presence of open spaces such as parks and gardens, and sustainable food production, the research concludes with a new strategy to meet the needs of urbanization in the twenty-first century, to become flexible A living environment, an incubator for all, safe and able to withstand future sustainable cities, and in pursuit of achieving research goals depends on some approaches, including the descriptive approach that collects information and sheds light on theoretical backgrounds, such as the deductive analytical approach to analyze information derived from theoretical and analytical study , And inferring the foundations, standards, scientific principles, and the comparative analytical method in order to monitor and analyze study samples. Using statistical analysis, the results are extracted and illustrated graphically using the columns method.