In recent years, the airport high coarse-granular fill construction in the southwest mountain area of China has entered a stage of rapid development, and coarse-grained soils such as rockfill materials with comparatively good engineering characteristics are widely used in high coarse-granular fill. The internal stress of high coarse-granular fill is large, and coarse-grained soil will cause particle breakage. It is of great engineering significance to analyze the impact of particle breakage characteristics on the deformation and stability of high coarse-granular fill. Modeling high coarse-granular fills using discrete element particle flow method. The deformation evolution process of the high coarse-granular fill is simulated through the strength reduction method. Based on the Russell & Muir Wood particle breakage criterion, two cases of particle breakage and don’t breakage were simulated and analyzed respectively. In addition, we also focus on the effect of particle fragmentation on the deformation and stability of the high coarse-granular fill. DEM modelling results indicate that the small-size grains abraded from the host coarse-granular grains will slip and fill the gaps among the host grains, leading to an increase in deformation and a decrease in the shear strength, and further resulting in a decrease in safety factor and stability of high coarse-granular fill.