<p>Wind-blown snow represents a prevalent phenomenon in polar and high-latitude regions, significantly influencing snow cover dynamics, hydrological cycles, and climate change processes. The collision fragmentation effect in wind-blown snow is more severe than that in other two-phase flows. However, existing wind-blown snow models mostly neglect this essential mechanism, significantly limiting the accuracy of wind-driven snow flow simulations and the predictive capability for snow-related disasters. This study utilizes the Discrete Element Method (DEM) to establish a fragmentation model for spherical snow particles in wind-blown snow, simulating the mid-air collision processes of particles with diverse collision speeds and angles. The intrinsic mechanisms and dominant factors governing snow particle fragmentation are elucidated. Results indicate that the normal component of collision velocity serves as the governing parameter regulating collision-induced fragmentation between snow particles. No significant differences in fragmentation characteristics are observed for collisions between same-sized particles. The number of effective fragments increases with increasing normal collision velocity, while the mass of the primary fragment decreases following a power function with a 52% reduction as the normal velocity increases. The particle size of small fragments exhibits a uniform distribution, ranging from 0.3 to 0.8 times the initial particle size, and the critical fragmentation velocity (the minimum velocity required for particle fragmentation) decreases linearly with increasing collision angles. Finally, a parameterized fragmentation model for the mid-air collision of snow particles is proposed, providing theoretical and modeling support for the improvement of wind-blown snow numerical models.</p> Graphical Abstract <p></p>