This　paper　lists　the　problems　during　the　stability　analysis　of　long　span　CFST　arch　bridge　and　the　corresponding　modeling　method.　Based　on　the　construction　control　of　an　orthotropic　long　span　CFST　arch　bridge,　a　FEM　model　had　been　established　to　analysis　the　stability　of　its　rib　during　the　concrete　pumping.　The　conclusion　shows　significant　importance　to　the　bridge＇s　construction　process.