In　this　paper,　we　proposed　a　32-bit　improved　adder　combined　with　sparse　tree　by　radix-2　and　carry　select.　We　designed　its　models-point　operation,　carry-out,　4-bit　ripple-carry　adder　and　4-bit　selector　by　reversible　logic,　and　designed　with　smic0.18um　process　corresponding　MOS　circuit　to　achieve.　The　simulation　results　could　verify　that　the　algorithm　and　the　design　by　reversible　logic　are　right.　©　2016　IEEE.