Abstract: At present, the frequency, scale and harm of public crisis events at home and abroad have increased significantly. How to deal with public crisis events scientifically, timely and effectively has become an urgent task of emergency management. This paper analyzes the evolution of emergency management theory and practice at home and abroad by using a bibliometric method, and discusses the common characteristics and practical experiences of emergency management system by comparing the evolution of emergency management practice in the United States, Japan, the United Kingdom and China. We find that the development of emergency management theory can be divided into three stages, namely, germination stage, outbreak stage and transition stage. The rapid growth of emergency management theory has promoted the transformation of emergency management practices from the single-hazard, comprehensive era to the "big national security" era. The joint defense-based emergency management mechanism based on collaborative governance has become a common feature of the current emergency management system, and crisis prevention and risk management have become the core contents of emergency management. Moreover, this paper discusses the current difficulties and breakthroughs in the development of emergency management theory and practice, redefines the connotation of emergency management, and proposes future research prospects. Based on chronological progressiveness and horizontal comparison, this paper analyzes the overall trend of emergency management theory and practice evolution, which has great value for clarifying the status of emergency management, as well as innovating the theory and practice mode of emergency management.

Key words: emergency management, theory evolution, practice evolution, dilemma and prospect