In　order　to　study　the　influences　of　natural　gas　pipeline　pressure　on　jet　fire　with　FDS(fire　dynamics　simulation)　software,　based　on　principle　of　fluid　mechanics　and　Thornton　flame　model,　characteristics　and　hazard　scope　of　the　jet　fire　were　comparatively　studied　for　different　pipe　pressure.　The　results　show　that　characteristics　and　hazard　scope　of　the　jet　fire　are　largely　affected　by　different　pressure.　When　the　pipe　pressure　is　0.2MPa　and　0.4MPa,　the　size　of　both　leak　holes　are　same,　during　a　same　period,　the　latter　flow　is　greater　than　the　former.　When　the　pipe　pressure　is　greater　than　0.8MPa,　the　leakage　hole　size　is　100mm,　and　the　maximum　temperature,　diameter　and　the　high　temperature　affected　area　of　the　flame　are　increased.　©　Published　under　licence　by　IOP　Publishing　Ltd.