This study investigates the complex interactions between gallium nitride (GaN) crystals and abrasives during double-grit grinding using molecular dynamics (MD) simulations. The research systematically examines grinding force, coefficient of friction, stress distribution, plastic damage behaviors, and abrasive damage. Key findings include: 1. **Grinding Quality**: Interacted distances in both radial and transverse directions improve grinding quality compared to single-direction interactions. 2. **Grinding Force and Friction**: The grinding force and coefficient of friction increase with transverse interacted distance, but there is no clear correlation with the number of atoms in phase transition or dislocation length. 3. **Stress Distribution**: The stress induced by the second abrasive decreases as the transverse interacted distance increases, while the stress on the subsurface gradually decreases and shifts to the region below the abrasives. 4. **Subsurface Damage**: The damage depth of the ground subsurface increases with the transverse interacted distance, but there is no clear correlation with the number of atoms in phase transition or dislocation length. 5. **Abrasive Damage**: Amorphization is the primary form of damage in abrasive wear, with more severe amorphization at the flank face due to high elastic recovery of residual material. The study validates the simulated results with grinding tests and cross-sectional transmission electron microscopy (TEM), confirming the presence of amorphous atoms, high-pressure phase transitions, dislocations, stacking faults, and lattice distortions. These findings enhance our understanding of damage accumulation and material removal during grinding and can guide the design of ordered abrasives for more efficient grinding processes.This study investigates the complex interactions between gallium nitride (GaN) crystals and abrasives during double-grit grinding using molecular dynamics (MD) simulations. The research systematically examines grinding force, coefficient of friction, stress distribution, plastic damage behaviors, and abrasive damage. Key findings include: 1. **Grinding Quality**: Interacted distances in both radial and transverse directions improve grinding quality compared to single-direction interactions. 2. **Grinding Force and Friction**: The grinding force and coefficient of friction increase with transverse interacted distance, but there is no clear correlation with the number of atoms in phase transition or dislocation length. 3. **Stress Distribution**: The stress induced by the second abrasive decreases as the transverse interacted distance increases, while the stress on the subsurface gradually decreases and shifts to the region below the abrasives. 4. **Subsurface Damage**: The damage depth of the ground subsurface increases with the transverse interacted distance, but there is no clear correlation with the number of atoms in phase transition or dislocation length. 5. **Abrasive Damage**: Amorphization is the primary form of damage in abrasive wear, with more severe amorphization at the flank face due to high elastic recovery of residual material. The study validates the simulated results with grinding tests and cross-sectional transmission electron microscopy (TEM), confirming the presence of amorphous atoms, high-pressure phase transitions, dislocations, stacking faults, and lattice distortions. These findings enhance our understanding of damage accumulation and material removal during grinding and can guide the design of ordered abrasives for more efficient grinding processes.