The subject of many urban studies is sustainable development and ideal approach of urban planners and designers in designing sustainable cities is mainly toward a better life and reduction of environmental crises. This article seeks to answer these questions What are the most important issues and problems of instability in the metropolis of Mashhad? What are the most important strategies for achieving a sustainable urban development model in Mashhad metropolis? The purpose of this study is to provide a strategic model for achieving sustainable urban development in Mashhad metropolis. To this end, the concepts and principles of sustainable urban development have been studied. Then, a variety of theories related to the development of urban sustainability including the city boom, compact city and smart city were studied, analyzed and summarized using conceptual analysis method. Finally, the initial conceptual model of the research was presented after reviewing the national documents and identifying the principles of planning. The model points out that in order to achieve sustainable urban development in Mashhad metropolis, the emphasis on a system management dimension with four dimensions of sustainability including physical, social, economic and environmental dimensions is necessary. In a quantitative evaluation of the conceptual model of the research using confirmatory factor analysis, the high path coefficient of environmental sustainability suggests that the most important urban instability problem in Mashhad metropolis is environmental instability. On the other hand, based on the views of the urban management team, presenting a comprehensive and participatory strategy model is the best way to achieve sustainable urban development in the metropolis of Mashhad.