A　nondestructive　testing　method　combining　ground　-penetrating　radar　(　GPR)　and　phased-array　ultrasonic　testing　(　PAUT)　was　proposed　to　address　the　difficulty　of　detecting　defects　on　the　bonding　surface　of　concrete　composite　slabs.　In　order　to　verify　the　method,　and　to　study　the　influence　of　reinforcement　on　the　detection　method,　a　single-layer　reinforced　composite　slab　and　a　double-layer　reinforced　truss　composite　slab　were　designed　and　fabricated.　On　the　bonding　surface,　three　types　of　artificial　defects　were　set,　delamination,voids,　and　debris.　The　detection　results　show　that　the　method　can　effectively　detect　all　defect　types　with　accurate　defect　localization.　The　relative　errors　of　detecting　the　size　of　defects　are　below　20.0%,and　the　average　errors　of　detecting　two　specimens　are　8.0%　and　6.　6%,　respectively,　the　relative　errors　of　detecting　the　depth　of　defects　are　below　10.0%,and　the　average　errors　of　detecting　two　specimens　are　4.3%　and　4.8%,　respectively.　This　method　is　an　effective　and　accurate　method　for　detecting　defects　in　the　bond　surface　of　concrete　composite　slabs.　©　2024　Chinese　Vibration　Engineering　Society.　All　rights　reserved.