Abstract: Under the combined effect of climate change and human activities, flood risks have gradually shown non-stationary characteristics, and their catastrophic features have also exhibited complex attributes such as low frequency and high loss,spatial correlation and loss chain effects, which have become important factors restricting regional security and sustainable development. Based on the literature review method, this paper systematically summarizes the research progress on the evolution law of flood disaster characteristics and risk assessment methods, analyzes the development status and applicability of methods such as frequency statistics, hydrological hydrodynamic coupling simulation, model structure optimization and parameter improvement, spatial data-driven and regional generalization, and explores the sources of uncertainty of different methods. In response to the problems of insufficient uncertainty quantification and unclear propagation paths in current research, it is proposed that future research should focus on collaborative analysis of multiple sources of uncertainty, analysis of uncertainty cascading transmission mechanisms, and modeling of physical constraints and data-driven fusion.