The principle of ultrasonic phased array and the classification of phased array probes are analyzed,and the application of ultrasonic phased array technique to the weld joint and forging inspection for power equipment is described. As compared with conventional ultrasonic testing,the ultrasonic phased array testing technique has the advantages of being fast and efficient,fit for complicated structural parts and capable of real-time imaging,etc.;therefore it is promising in the nondestructive testing field of power industry.