Abstract: Defect location, representative defect and its ultrasonic echo characteristics corresponding of tungsten alloy shells had been systematically studied by both vertical wave sensors and transverse wave sensors calibrated after manufacturing. The results showed that, defects such as the hole, crack, bird’s net and the like, could be inspected using ultrasonic testing method. The echo of single hole was high, its front was steep edge; the echo of dense hole was connected and uneven; the echo of crack was high and keen-edged, the bottom echo was decline in some certain; the echo root of bird’s net had some small wave followed.