To　satisfy　the　need　for　the　design　of　the　National　Fitness　Center　in　Ejin　Horo　Banner,　Inner　Mongolia,　the　fire　resistance　performance　of　the　cable　dome　structural　system　is　studied　in　the　paper.　Considering　material　nonlinearity　under　high　temperature,　the　structural　response　under　different　fire　conditions　and　the　basic　laws　of　structural　deformation,　node　displacement　and　prestressing　force　loss　were　analyzed,　based　on　thermal-structural　coupling　method　and　the　model　of　atmosphere　temperature　ascending　in　large　space.　This　research　indicates　that　the　lateral　stiffness　of　Geiger　cable　dome　structure　is　weak　and　it　is　susceptible　to　eccentric　fire　load;　the　eccessive　deflection　and　lateral　deformation　are　major　reasons　for　structural　failure　and　nonstructural　components＇　early　damage　under　fire.　The　pestressing　force　loss　of　the　ridge　cables,　especially　the　inner　ridge　cables,　is　more　serious,　and　the　struts　should　be　considered　as　key　parts　in　the　fire　resistance　design.　Finally,　for　the　deficiency　of　plane　stiffness　in　Geiger　cable　dome　structure,　the　improvement　of　adding　loop　rigid　rods　on　the　upper　node　of　struts　can　benefit　the　fire　resistance　performance　significantly.