Due to the complex and variable operating conditions of the turbine rotor blades,it is easy to produce crack hazard defects at the roots,which puts higher requirements to the speciality,safety,stability and convenience of ultrasonic testing.How to find the deficiencies in the ultrasonic inspection and improve it so that it can better adapt to the on-site inspection has become a topic of concern.The working principle of ultrasonic phased array inspection technology was briefly introduced.The selection of inspection technology and inspection equipment,ultrasonic phased array inspection process and problems in the inspection process were discussed in detail.Suggestions for improvement were also proposed.The final phased array inspection technology has used to find significant hazardous crack defects in field,which can be promoted in the field of nuclear power nondestructive testing.