In the rapid urbanization process, uncertain and diverse disturbances pose a threat to urban development. Enhancing the city's ability to absorb, resist, adapt and study has become a hot topic that needs to be resolved urgently. As a new paradigm for cities to deal with uncertain risks, a resilient city has guide significance for improving urban resilience and emergency response capability. This paper discriminates resilience detail, which realized the cognitive changes from engineering, ecological, and evolutionary perspectives, then compares resilience with recovery and elasticity. It puts forward the idea about the concept of urban resilience of multi-factor integration, multi-capacity transformation, and multi-temporal and spatial scales based on the study of existing concepts of urban resilience. In this study, the concept of urban resilience is the ability of the whole urban system to optimize resilience independently in the current and future periods. It reflects an ability to face disturbances by integrating and exerting the functional role of various urban elements (including economy, society, organization, ecology, infrastructure), mobilizing the participation of multiple subjects such as urban individuals, communities, social organizations, and governments. It improves urban resilience by coping capacities of prevention, resistance, recovery, learning, adaptation, and transformation. Based on the concept of urban resilience proposed above, the paper systematically summarizes the impact of multiple disturbances, city system status, and urban coping capabilities on urban resilience from a process perspective. The single-domain and multi-domain assessments of urban resilience are sorted out. Three assessment index systems based on urban resilience elements, urban resilience characteristics, and the process of urban resilience realization are discussed in detail. And qualitative and quantitative urban resilience assessment methods are summarized and compared. Through the above analysis, the paper clarified the weaknesses, such as lacking of research on how to achieve urban resilience, paying less attention to the organizational factors, diverse disturbances and multiple subjects to evaluation indicators, lacking the application of mechanism and dynamic simulation about evaluation method, derailing between theory and practice. At last, the paper put forward the research prospects. That is, further work should pay more attention to process analysis of how the city achieves resilience rather than the result of the city's resilience, and try to design a more complete and targeted indicator system by introducing multi-source data. In addition, studies should continue to promote the scientific and dynamic improvement of research methods, and aim to strengthen the formation of an operable closed loop of mechanism-evaluation-management oriented by empirical research.