With　the　rapid　development　of　technologies　such　as　wireless　communications　and　the　Internet　of　Things　(IoT),　the　proliferation　of　IoT　devices　will　intensify　the　competition　for　spectrum　resources.　The　introduction　of　cognitive　radio　technology　in　IoT　can　minimize　the　shortage　of　spectrum　resources.　However,　the　open　environment　of　cognitive　IoT　may　involve　free-riding　problems.　Due　to　the　selfishness　of　the　participants,　there　are　usually　a　large　number　of　free-riders　in　the　system　who　opportunistically　gain　more　rewards　by　stealing　the　spectrum　sensing　results　from　other　participants　and　accessing　the　spectrum　without　spectrum　sensing.　However,　this　behavior　seriously　affects　the　fault　tolerance　of　the　system　and　the　motivation　of　the　participants,　resulting　in　degrading　the　system＇s　performance.　Based　on　the　energy-harvesting　cognitive　IoT　model,　this　paper　considers　the　free-riding　problem　of　Secondary　Users　(SUs).　Since　free-riders　can　harvest　more　energy　in　spectrum　sensing　time　slots,　the　application　of　energy　harvesting　technology　will　exacerbate　the　free-riding　behavior　of　selfish　SUs　in　Cooperative　Spectrum　Sensing　(CSS).　In　order　to　prevent　the　low　detection　performance　of　the　system　due　to　the　free-riding　behavior　of　too　many　SUs,　a　penalty　mechanism　is　established　to　stimulate　SUs　to　sense　the　spectrum　normally　during　the　sensing　process.　In　the　system　model　with　multiple　primary　users　(PUs)　and　multiple　SUs,　each　SU　considers　whether　to　free-ride　and　which　PU＇s　spectrum　to　sense　and　access　in　order　to　maximize　its　own　interests.　To　address　this　issue,　a　two-layer　game-based　cooperative　spectrum　sensing　and　access　method　is　proposed　to　improve　spectrum　utilization.　Simulation　results　show　that　compared　with　traditional　methods,　the　average　throughput　of　the　proposed　TL-CSAG　algorithm　increased　by　26.3%　and　the　proposed　method　makes　the　SUs　allocation　more　fair.