Silicon　carbide　(SiC)　removal　process　was　simulated　by　smoothed　particle　hydrodynamics　and　finite　element　method　(SPH-FEM)　with　double　diamond　abrasive,　SPH-FEM　could　prevent　the　influence　of　mesh　distortion.　The　results　show　that　there　are　three　interference　modes　while　scratching:　plastic　damage　interference,　plastic　damage　and　lateral　crack　interference,　and　lateral　crack　interference.　With　the　increase　of　double　diamond　abrasive　distance,　the　interference　region　groove　width　increases　linearly,　but　the　interference　region　groove　depth　decreases.　When　the　interference　mode　is　stable,　the　groove　depth　nearly　remains　constant.　When　the　interference　mode　changes,　the　maximum　width　to　depth　ratio　of　the　interference　region　will　change　significantly.　The　average　scratching　force　of　SiC　will　fluctuate　with　the　change　of　interference　mode.　In　the　lateral　crack　interference　mode,　the　groove　width　is　large,　the　subsurface　damage　is　small,　the　width　to　depth　ratio　of　the　interference　region　is　large,　which　means　that　the　large　width　to　depth　ratio　helps　reduce　subsurface　damage.　It　is　more　conducive　to　the　removal　of　materials　and　improve　the　surface　quality　after　scratching.