There is so much influence to the fatigue life of the whole structural component from cross-section transition zone radian, and more than 100 times difference is made by different structural details for fatigue life . According to structure and features of variable cross-section strut-and-tie,combing with its’ geometric properties and applied stress ways, at the basis of nominal stress method, the fatigue life of variable cross-section strut-and-tie is analyzed in the paper. Then, transitional zone is improved and fatigue life is analyzed. At last, the improved is compared with previous structure and analysis of Influence of fatigue life from variable cross-section strut-and-tie transition zone radian in theoretical. The conclusions of this paper guide other similar researches.