Abstract: Analytic geometry theories and methods were applied to found the mathematical model of welds in TKY tubular node.According to the regulation of the size,welded joints were drawn after getting weld cross-section in tubular node.The ultrasonic phased array probe profile was designed on the basis of its physical size,and ultrasonic beam was also designed.The computer-aided technology can achieve the beam coverage of welded joints,which can commendably guide the design of ultrasonic phased array inspection and evaluate ultrasonic test blind areas of weld in TKY tubular node.The blindness of setting parameters can be overcome in the course of ultrasonic phased array inspection.Tests of weld in artificial Y tubular node indicated that the combination of ultrasonic phased array imaging technology and computer-aided techniques contributed to rapid detection and evaluation of weld in tubular node.