Inordertoimprovetheperformanceofthemainarchofthelarge-spanCFSTarch bridge， a new idea on the initial stress release and transfer of the steel tube was presented.Take debonding measures for steel tube before pouring concrete， after the concrete is poured and the strength is reached， cutting off the steel tube to allow the initial stress of the steel tube to be transferred to the core concrete， and then reconnected the steel tube so that it to-get her with the concrete bears the follow-upload.According to the above ideas， the finite element method was used to analyze the case of a single piper i bCF STarch bridge and a truss rib CF STarch bridge.The analysis shows that without friction the initial stress of the steel tube can be effectively released and transferred to the core concrete after the steel tube is cutoff.Compared with the original design， after the initial stress release and transfer，the stress on the steel tube of the arch rib is significantly reduced under the completion state.For the truss CF STarch bridge， the maximum stress can be reduced by 14.5%.Consid ering the confining effect， the stress of concrete filled steel tube is greatly increased， but still under the compressive strength of concrete.It proves that this method can significantly improve the combination efficiency of arch rib section of the large-span CF STarch bridge，and improve the performance of the main arch rib.