Abstract: In this paper, various transverse wave ultrasonic testing (UT) parameters influencing the echo waveforms resulting of 6063 aluminum alloy weld were studied and analyzed. Experiments on the change of the inspection angle, frequency and diameter of ultrasonic transducer and echo waveform of defection with the parameters were conducted. The results showed that with increasing the frequency, ultrasonic testing sensitivity of the defects increased first but then decreased, and better sensitivity for the aluminum alloy bus weld testing by UT was obtained when the frequency was 5 MHz; Chip dimension was mainly influencing probes near field zone length. When the work piece thickness was less than 15 mm, it was recommended to use 36 mm2 chip (with K being 2) for ultrasonic inspection for the aluminum alloy bus weld. Due to the fact that the echo waveform amplitudes of the defects were almost changed with the inspection angle of the probes, and when the work piece thickness was less than 17 mm, the amplitude curve of the defects increases with increasing the inspection angle for a circular hole. Better sensitivity for the aluminum alloy bus weld testing was obtained when the frequency of transverse wave probe is 5 MHz, the inspection angle was larger angle, and chip size was small.