A　hollow　tungsten　negative　pressure　arc　(HTNA)　is　a　heat　source　that　controls　the　gas　flow　inside　a　tungsten　electrode　and　optimizes　the　arc　output.　However,　to　ensure　the　widespread　applicability　of　HTNAs,　the　factors　affecting　the　temperature　and　pressure　distribution　of　an　HTNA　should　be　studied.　In　this　study,　the　effect　of　pumping　gas　on　the　temperature　and　pressure　distribution　of　an　HTNA　is　elucidated　through　experiments　and　numerical　simulations.　A　double　spectral　line　acquisition　system　with　nine　optical　transmission　fibers　was　used　to　obtain　the　arc　light　intensity　for　the　temperature　calculation　and　spatial　reconstruction.　Consequently,　a　unified　numerical　model　was　developed　to　quantitatively　study　the　physical　field　distribution　under　the　effect　of　pumping　gas.　It　was　observed　that　the　maximum　temperature　of　the　traditional　gas　tungsten　arc　(GTA)　and　hollow　tungsten　arc　(HTA)　decreased　more　than　that　of　the　HTNA　owing　to　the　effects　of　pumping　gas.　By　analyzing　the　current　density　and　flow　field,　it　was　concluded　that　convective　heat　transfer　owing　to　pumping　gas　is　the　primary　cause　of　the　temperature　difference　between　the　arcs　rather　than　Joule　heat.　Compared　with　the　effect　of　the　Lorenz　force,　the　arc　flow　had　a　more　significant　effect　on　the　pressure　difference　between　the　inner　and　outer　tungsten　electrodes.　The　gas　in　the　arc　region　flowing　into　tungsten　also　affected　the　arc　pressure　on　the　base　metal　surface.　The　results　of　this　study　are　expected　to　provide　guidance　for　controlling　the　energy　output　of　the　welding　arcs.