The　baffle　effectively　slowed　down　debris　flow　velocity,reduced　its　kinetic　energy,and　significantly　shortened　the　distance　of　debris　flow　movement.Consequently,they　are　widely　used　for　protection　against　natural　hazards　such　as　landslides　and　mudslides.This　study,based　on　the　three-dimensional　DEM(Discrete　Element　Method),investigated　the　impact　of　different　baffle　positions　on　debris　flow　protection.Debris　flow　velocity　and　kinetic　energy　variations　were　studied　through　single-factor　experiments.Suitable　baffle　positions　were　preliminarily　selected　by　analyzing　the　influence　of　the　first-row　baffle　position　on　the　impact　force　and　accumulation　mass　of　debris　flow.Subsequently,based　on　the　selected　baffle　positions　and　four　factors　influencing　the　effectiveness　of　baffle　protection(baffle　position(P),baffle　height(h),row　spacing(Sr),and　angle　of　transit　area(α)),an　orthogonal　design　was　employed　to　further　explore　the　optimal　arrangement　of　baffles.The　research　results　indicate　that　the　use　of　a　baffle　structure　could　effectively　slow　down　the　motion　velocity　of　debris　flows　and　dissipate　their　energy.When　the　baffle　is　placed　in　the　transit　area,the　impact　force　on　the　first-row　baffle　is　greater　than　that　when　the　baffle　is　placed　in　the　deposition　area.Similarly,when　the　baffle　is　placed　in　the　transit　area,the　obstruction　effect　on　debris　flow　mass　is　also　greater　than　that　when　the　baffle　is　placed　in　the　deposition　area.Through　orthogonal　experimental　range　analysis,when　the　impact　on　the　first　row　of　baffles　is　used　as　the　evaluation　criterion,the　importance　of　each　influencing　factor　is　ranked　as　α＞P＞Sr＞h.When　the　mass　of　debris　flow　behind　the　baffle　is　regarded　as　the　evaluation　criterion,the　rank　is　changed　to　P＞α＞Sr＞h.The　experimental　simulation　results　show　that　the　optimal　baffle　arrangement　is:P5,Sr=16,α=35°,h=9.