A　topology　optimization　design　method　for　prestressed　steel　structures　system　innovation　was　proposed.　The　optimization　mathematical　model　was　established　in　such　form　that　cables＇　pretension　force　and　structural　topology　were　design　variables,　the　structural　displacement　was　constrain　condition,　and　the　minimum　structural　weight　was　objective　function.　In　order　to　solve　the　problem,　two-stage　design　method　was　adopted.　The　cables＇　pretension　force　could　be　determined　by　minimizing　structural　strain　energy　(maximizing　structural　stiffness).　After　that,　the　method　of　evolutionary　structure　optimization　(ESO)　was　applied　to　achieve　structural　topology　optimization　by　deleting　elements　with　low　displacement　sensitivity,　and　the　structural　weight　was　also　reduced.　Two-stage　iterated　alternately　until　structural　topology　achieved　optimum.　The　example　results　coincided　with　the　corresponding　structural　performance,　which　indicated　the　proposed　optimization　design　method　was　practicable　and　could　provide　theoretical　method　for　prestressed　steel　structures　type　selection.