This　paper　is　to　analysis　the　influence　factor　on　failure　modes　of　light　steel　column　under　high　temperature　and　explosion,　the　numerical　analysis　methods　and　results　will　further　provide　the　basis　for　proposed　damage　assessment　methodology　of　the　light　steel　column　under　high　temperature　and　explosion.　The　dynamic　finite　element　software　ANSYS/LS-DYNA　is　used　for　the　numerical　simulation,　according　to　the　EUROCODE3　under　different　temperatures　with　steel　constitutive　relation,　considering　the　strain　rate　effect　and　the　Cowper-Symonds　criterion.　The　numerical　results　indicate　that　the　destruction　of　the　light　steel　column　is　more　serious　at　the　high　temperature　than　that　at　the　normal　temperature　and　the　higher　temperatures,　the　greater　blast　loading.　When　θ＞400°C,　the　column　failures.　The　destruction　will　be　serious　with　decreasing　of　the　scaled　distance　of　the　light　steel　column　under　the　same　support　style.　For　different　support　styles,　the　light　steel　columns　have　different　failure　modes.　The　typical　failures　include　three　types.　The　first　one　is　direct　shear　failure　for　the　column　fixed　at　both　ends.　The　second　is　the　combination　of　the　shear　and　flexure　failures　for　the　column　with　a　fixed　end　and　a　pin　end.　The　third　is　flexural　failure　for　the　column　with　both　pin　ends.