Abstract: For the special shape of drill tube such as big thickness/diameter ratio, complex shape and types of model, it was very difficult to inspect it with ultrasonic testing. The ultrasound scanning ways covering the total axial, circumferential and sloped zone of drill tube were researched. The special combined probe arrays inspecting the axial and circumferential defects were designed and were installed on a special stand. Testing results showed that the scanning ways and probe arrays could test both the axial and circumferential defects in the drill tube both effectively.