A　spring　model　method　is　established　for　researching　wave　characteristics　of　the　weak　bonded　structure,　which　is　used　to　change　the　resonance　frequency　and　reflection　coefficient.　According　to　the　relationship　between　the　ultrasonic　propagation　characteristics　and　stress-strain　condition,　the　reflection　coefficient　of　the　bonding　layer　with　zero　thickness　is　derived.　The　reflection　of　wave　for　equal-thickness　aluminum　plates　under　the　thickness　of　the　bonding　layer　is　calculated.　Analysis　and　computation　show　that　resonance　frequency　curves　can　engender　on　the　shift　of　＇the　shift　right　peaks＇　with　the　effect　of　the　variety　of　the　interface　stiffness.　The　influences　on　the　multi-mode　resonance　frequency　of　a　layered　structure　with　the　thickness　of　the　adhesive　layer　are　calculated,　and　the　influence　of　the　＇multi-peak＇　of　resonance　frequency　curves　is　discussed.