To investigate the influence of artificial sandbars on beach profile evolution, we conduct mobile-bed physical model experiments in a wave flume under JONSWAP random wave conditions, incorporating composite-slope beach profiles.On the basis of experimental data, we analyze the characteristics of wave propagation, cross-shore sediment transport, and profile evolution patterns, with a focus on the effects of sandbar placement, height, and median grain size.The results show that intense wave breaking at the sandbar crest induces a significant reduction in fundamental frequency energy and minimum transmission coefficient is 0.4, accompanying by prominent low-frequency wave components behind the sandbar, the motion of higher harmonics becomes more complex, and the nonlinear characteristics of local waves on the sandbar are enhanced.Sediment transport is dominated by bedload transport and facilitated onshore sand replenishment, resulting in upper beachface erosion combined with berm and lower beach face deposition, contrasting with consistent erosion and offshore sediment transport observed in non-sandbar configurations.Among the experimental conditions sandbar height exhibits the most pronounced protective effect to the beach face.When the sandbar crest aligns with still water level, unit-width erosion volume, berm erosion depth, and shoreline retreat distance decreases by 89%, 69%, and 90%, respectively.