With　the　development　trend　of　the　Intelligent　Internet　of　Things　(IoT)　society,　the　infrastructure　of　the　IoT　is　increasing,　and　the　use　of　RFID　technology　as　the　core　of　the　IoT　system　is　also　more　extensive.　Strengthening　the　security　of　IoT　infrastructure　has　become　a　top　priority.　Most　of　these　IoT　infrastructures　are　resource　constrained,　so　lightweight　encryption　algorithms　are　used　to　ensure　the　communication　security　between　IoT　devices.　This　paper　proposes　a　lightweight　encryption　algorithm　named　＇SWLEA＇.　The　data　block　length　of　the　algorithm　is　32-bit,　and　supports　32-bit　key.　The　algorithm　is　mainly　applicable　to　the　system　with　RFID　tag　chip　as　the　identifier　chip.　©　2022　IEEE.