Flexible barriers are widely used as countermeasures against debris flows due to their lightweight components, such as cables and nets, which make them relatively easy to construct. As a result, they are often deployed as emergency measures post‐disaster to protect construction sites for Sabo dams. Additionally, flexible barriers are considered effective countermeasures for small streams where the construction of Sabo dams. However, the interaction between debris flows and flexible barriers is highly complex, and several studies are required to fully understand the phenomena. In particular, the buffering effect of the flexible barrier remains insufficiently understood. Therefore, it is important to investigate the buffering effect in detail. This study focuses on the buffering effects of flexible barriers. Experiments were conducted using both a flexible barrier and a rigid barrier to evaluate the buffering effect of flexible barrier. Debris flows with varying flow velocities were generated to examine how flow velocity influences the buffering effect. The experimental results show that the impact force exerted by debris flow on the flexible barrier was reduced by up to half compared to that on the rigid barrier. Additionally, the rate of force for the flexible barrier is also lower than that of rigid barrier. These findings indicate that the buffering effect of flexible barriers mitigate the impact force of debris flow from the moment of collision. Although both impact force and the rise rate increased with higher flow velocities, the buffering effect was more pronounced at lower flow velocities. This suggests that flow velocity significantly influences the buffering effect of flexible barriers.