Aiming　at　the　demand　for　improving　the　heat　release　performance　of　solid　propellants　for　high　energy　and　complex　practical　application　scenarios,　the　B-Mg-Al　ternary　alloy　is　proposed　as　a　metal　fuel　additive.　Based　on　the　unique　phase　distribution　of　B-Mg-Al　ternary　metal　alloy　and　the　existing　theory　of　ignition　and　combustion　of　metal　particles,　the　kinetic　simulation　of　ignition　and　combustion　of　B-Mg-Al　ternary　metal　alloy　particles　in　complex　alternating　atmosphere　is　carried　out　by　combining　with　the　virtual　alternating　atmosphere　environment.　The　model　calculates　the　combustion　time　tc　of　10　mu　m　B-Mg-Al　alloy　particles　in　H2O(g),　H2O(g)/Air　alternating　mode,　and　Air　to　be　3.50　ms,　3.98　ms,　and　4.60　ms,　respectively,　and　the　comparative　errors　with　the　experimental　measurement　of　combustion　time　are　kept　around　5%,　which　verifies　the　reliability　of　the　model　results.　The　simulation　study　shows　that　the　order　of　thermal　oxidation　reaction　and　the　order　of　combustion　of　the　monomolecular　group　elements　of　B-Mg-Al　ternary　alloy　particles　are　Mg,　Al,　and　B,　which　to　some　extent　indicates　that　the　addition　of　Mg　and　Al　has　the　potential　to　improve　the　ignition　and　combustion　performance　of　B.　In　addition,　there　are　obvious　differences　in　the　ignition　and　combustion　performance　and　heat　transfer　performance　of　the　alloy　particles　under　H2O(g)　and　that　of　Air　with　the　same　concentration,　which　leads　to　significant　instability　in　both　ignition　and　combustion　processes　at　variable　medium.