Abstract: Analysis and research on the wave type and mechanism of the creeping wave were made.According to the requirement of the wires and bars for the ultrasonic testing,self-developed creeping wave probe using line focus single chip was proposed for the ultrasonic creeping wave detection of wires and bars.Various results using creep wave ultrasound testing of wires (diameter less than 3 mm) and small bars (diameter not greater than 12 mm) of different materials with different locations and sizes of artificial and natural crack,respectively were given.The results show that the ultrasonic creeping wave detection method is feasible and effective.