Focusing on the characteristics of diversity, complexity, and linkage in the formation process of urban flooding disasters, the composition and formation mechanism of urban flooding disasters was analyzed, the uncertainty, instability, and non-uniformity characteristics of the urban flooding disaster risk were summarized, and the exposure, vulnerability, and fragility of the disaster-bearing bodies in the disaster-causing urban flooding were investigated. The applicability of H-V, H-E-V, and H-E-V-R frameworks in urban flooding disaster risk assessment was compared, the process of urban flooding disaster risk assessment was proposed, and the applicable conditions, advantages and disadvantages of historical disaster assessment method, index system assessment method, GIS and RS coupling method, scenario simulation assessment method, and multi-agent model evaluation method were investigated. It is pointed out that future risk assessment methods for urban flood disasters will evolve from qualitative analysis to quantitative evaluation, and the focus of assessment will shift from the flood disasters themselves to the disaster-bearing bodies.