Our company PSX can use digital ultrasonic flaw detector to detect titanium alloy bars, the maximum sampling rate is 240MHz, the minimum display range is 5mm, the working frequency range is 1-10MHz, the sensitivity margin is 62dB. the probe is a longitudinal wave straight probe, specification is 5Z14N. this portable flaw detector is the main instrument for manual flaw detection. Titanium alloy bar can be ultrasonic flaw detection by direct contact method, using ultrasonic flaw detection, metallographic analysis and hardness test to study the correspondence between the waveform characteristics of different types of metallurgical secondary defects and defect morphology. By observing the static waveform characteristics of metallurgical defects at different locations and the changing law of dynamic waveforms, combined with microstructure characteristics, the corresponding relationship between microscopic morphology characteristics of metallurgical defects and flaw detection waveforms is established.