Based　on　the　properties　and　stress　characteristics　of　space　frame　structures　under　fire,　the　nonlinear　finite　element　numerical　simulations　are　performed　on　the　properties　of　the　welded　hollow　spherical　joints　bearing　axial　compression　under　fire　with　the　thermal　parameters　specified　in　the　EUROCODE　3　and　the　standard　fire　temperature-time　curve　ISO834.　The　distribution　law　and　influencing　factors　of　the　temperature　fields　are　analyzed.　By　analyzing　the　stress　and　displacement　variation　characteristics　of　the　welded　hollow　spherical　joints　under　fire,　their　failure　modes　are　determined.　The　results　show　that　decreasing　the　load　ratio　or　increasing　the　thickness　of　the　welded　steel　pipe　can　prolong　the　ultimate　fire-resistant　duration,　and　the　steel　tube　root　is　the　weakness　of　the　welded　hollow　spherical　joint　bearing　compression　under　fire.