A　topology　optimization　design　method　for　prestressed　plane　entity　steel　structures　is　proposed.　The　optimization　mathematical　model　is　established　in　such　a　form　that　the　cables＇　pretension　force　and　the　structural　topology　are　design　variables,　the　structural　total　strain　energy　is　constrain　condition,　and　the　minimum　structural　weight　is　the　objective　function.　Then,　the　cables＇　pretension　force　can　be　determined　by　minimizing　structural　strain　energy　(maximizing　structural　stiffness).　After　that,　the　method　of　evolutionary　structure　optimization　(ESO)　is　applied　to　achieve　structural　topology　optimization　by　deleting　elements　with　low　strain　energy,　and　the　structural　weight　is　also　reduced.　The　example　result　coincides　with　the　corresponding　structural　performance,　which　indicates　the　proposed　optimization　design　method　is　feasible.