Floods pose significant threats to farmers, and engaging in effective disaster avoidance behaviors can mitigate some of these risks for farmers in flood risk areas (FRA). However, due to farmers' bounded rationality char-acteristics, they often have a cognitive bias of blindly overestimating or underestimating flood risk, thus failing to perform correct disaster avoidance behaviors. Based on survey data from 180 farmers in FRA in southwest China, this study constructs an assessment method for farmers' subjective and objective flood risk and analyzes the characteristics of farmers' subjective and objective flood risk. A probit regression model explores the correlation between subjective and objective flood risk consistency and farmers' willingness to purchase natural disaster insurance (WPNDI). Results showed that of the 180 farmers surveyed, 63.89% had inconsistent subjective and objective flood risks, mainly reflected in an underestimation of objective flood risk. Farmers' subjective and objective flood risk consistency was found to be positively and significantly correlated with their WPNDI. When other conditions remain unchanged, for every unit increase in the consistency of farmers' subjective and objective flood risk, their WPNDI increased by 0.601 units on average. This paper originally proposed the hy-pothesis that the consistency of farmers' subjective and objective flood risk is positively and significantly correlated with their WPNDI, and proved the reliability of this hypothesis through research. These findings can provide policy references for disaster risk management and resilient disaster prevention system construction in FRA.