I am working for Bao steel-special steel Company, I have been arranged as a ultrasonic operator for many years. Testing titanium alloy is very meticulously, normally the isolate is Φ0.6~Ф0.8mm﹑signal-to-noise ratioΦ0.6-12dB~Ф0.8-12dB。It is difficult to find the way to inspect and judge the defect that is hidden in grass when we do ultrasonic testing for titanium alloy. Currently,it is hard to achieve whatever it is use modern digital instrument or analogue instrument ; Whatever we use immersion testing or direct contact method. Now I would like to study and discuss it based on experience and knowledge I have learnt.