According　to　the　ultrasonic　propagation　characteristics　and　spring　model　condition,　the　relationship　between　the　reflection　coefficient　of　bonding　interface　and　incidence　angle　under　once　reflection　echo　was　derived,　the　influence　on　the　reflective　properties　of　bonding　interface　with　the　change　of　bonding　material　were　studied,　and　the　reflection　coefficients　of　weak　bonding　interface　with　different　stiffness　ratio　and　incidence　angle　were　calculated.　Numerical　simulation　results　show　that　when　oblique　incidence　wave　is　S-wave,　there　is　a　critical　angle,　and　the　reflection　coefficient　changes　greatly　under　the　critical　angle;　critical　angle　varies　with　the　changing　of　the　upper　material,　and　the　reflection　coefficient　reaches　the　minimum　under　the　critical　angle;　when　debonding,　with　the　increase　of　the　critical　angle,　the　minimum　reflection　coefficient　decreases;　for　the　weak　bonding　interface,　with　the　stiffness　ratio　decreases,　the　reflection　coefficient　drifts　upward　when　the　incidence　angle　is　smaller　than　a　certain　angle.