Based　on　the　non-contact　ultrasonic　testing　method,　the　bonding　quality　of　composite　bonding　structure　is　simulated　and　experimentally　explored.　Firstly,　the　time-domain　simulation　model　of　ultrasonic　transmission　characteristics　of　composite　bonded　structures　is　established,　the　frequency-domain　transmission　coefficient　spectrum　is　extracted,　and　the　effects　of　interface　weakening　and　cohesion　weakening　on　ultrasonic　transmission　characteristics　of　bonded　structures　are　analyzed.　At　the　same　time,　the　spectrum　of　ultrasonic　transmission　coefficient　in　different　bonding　states　is　in　good　agreement　with　the　calculation　results　of　plane　wave　theory.　In　addition,　fiber　reinforced　composite(FRP)　bonding　structures　with　different　bonding　interface　states　and　adhesive　layer　cohesion　weakening　states　were　prepared.　Based　on　the　water　immersion　ultrasonic　measurement　system,　the　effects　of　different　bonding　interface　states　and　cohesion　weakening　states　on　the　ultrasonic　transmission　coefficient　spectrum　are　experimentally　investigated.　The　relationship　between　the　ultrasonic　transmission　characteristics　in　the　bonding　structure　and　the　bonding　quality　is　analyzed,　which　is　consistent　with　the　simulation　results.　In　addition,　according　to　the　mapping　relationship　between　bonding　quality　and　ultrasonic　transmission　characteristics　in　composite　bonding　structures,　it　also　lays　a　solid　foundation　for　nondestructive　characterization　and　evaluation　of　composite　bonding　structures.　©　2024　Chinese　Mechanical　Engineering　Society.　All　rights　reserved.