The flaw detector adopts advanced phased array ultrasonic flaw detection technology, It has the function of large-range continuity angle self-focusing scanning, No need to replace various angle probes, simple operation, high flaw detection efficiency, multi-sound beam and multi-angle detection for the same defect, accurate defect positioning, compatible with traditional ultrasonic probes, suitable for manual flaw detection of wheels, axles and key components, and also suitable for checking defects detected by automatic flaw detection equipment of wheels and axles.