Abstract: With global climate change, the frequency and intensity of flash floods have significantly increased, posing a serious threat to people's lives and property safety. Taking the "6·16" extremely heavy rainstorm and flash flood disaster in 2024 in Meizhou City, Guangdong Province as an example, the formation process and causes of flash flood disasters are analyzed through comprehensive analysis of natural and social factors such as rainfall, water regime, topography, etc. The results indicate that short-term heavy rainfall is the direct cause of flash flood, and terrain conditions promote flood formation. The extreme nature of rainfall and insufficient awareness of diversion and risk avoidance lead to severe losses. Suggestions are proposed for improving monitoring, forecasting, and early warning capabilities, conducting risk investigations and identifying key hidden dangers, implementing engineering measures, and building grassroots monitoring and prevention systems to provide reference for the prevention of flash flood disasters.