Abstract: In order to solve the problem that the ultrasonic inspection of special-shaped thin-wall pipe is not easy to use the conventional circular pipe inspection technology, the ultrasonic creeping wave technology is used to realize the ultrasonic inspection of hexagonal pipe in this paper. A layout of probe is designed according to the pipe structure characteristics. By using the hexagon shaped pipe block with artificial defects, the ultrasonic creeping wave beam is verified to cover full volume of hexagonal special-shaped pipe. This method can detect all the defects in the artificial test block, which is an effective method for the ultrasonic examination of hexagonal pipe.