Abstract: An ultrasonic phased array testing system was presented and developed for tube detection, as the conventional testing equipment usually encountered the unsteadiness, low SNR and low detection efficiency. The system has six sets of transmitting and receiving boards and collecting and processing boards. Each set has 16 independent channels. There are 96 channels totally. The system also has a set of ultrasonic phased array control and display software, which can display the test results in a variety of imaging modalities instantly. The experiment analyses have been carried out with two different sizes of the tubes. It shows that the system has high efficiency, flexibility, reliability, and other advantages.