To　study　the　shape　determination　and　solve　the　self-stress　modes　of　cable-truss　tensile　structures,　an　improved　force　iteration　method　based　on　reasonable　shape　was　proposed　by　the　finite　element　software　ANSYS.　Firstly,　a　simple　formula　for　shape　determination　was　derived　from　the　rational　shape　based　on　the　topological　relation　of　the　cable-truss　tensile　structure.　Then,　an　improved　force　iteration　method　was　proposed　to　solve　the　self-stress　modes　of　the　cable-truss　tensile　structures.　In　the　iteration　process,　the　updated　cable　forces　were　gradually　close　to　the　target　values,　and　the　unbalanced　displacements　of　the　structure　under　target　pre-stresses　were　obtained.　The　results　of　examples　show　that　the　cable-truss　frame　with　reasonable　shape　is　determined　by　one-time,　and　the　self-stress　mode　is　obtained　after　about　5　iterations.　The　largest　error　between　the　results　of　the　proposed　method　and　those　of　the　existed　method　is　0.48%,　meeting　the　engineering　requirements.　After　the　self-stress　mode　obtained　from　the　plain　cable-truss　frame　is　put　into　the　spatial　cable-truss　tensile　structure,　the　calculation　results　are　close,　and　the　largest　error　of　the　internal　forces　is　0.030%.　The　unbalanced　displacements　are　small,　proving　the　feasibility　of　the　assembly　of　spatial　cable-truss　tensile　structures　by　plain　cable-truss　frames.　©　2020,　Editorial　Department　of　Journal　of　Southeast　University.　All　right　reserved.