Abstract: The shear and longitudinal wave detection cannot be realized simultaneously in the thick wall steel pipe,whose ratio of thickness to radius is more than 0.2 Aiming at this problem,through the analysis of the detecting principle of thick wall steel pipe,a software system of ultrasonic flaw detection for high pressure seamless thick wall steel pipe based on VC++ is designed,and the design idea and technical implementation key points of software are stated.This software system implements some functions of the real-time acquisition,filtering processing,echo display,defects diagnosis and report print and the 20×6mm thick wall seamless steel pipe is detected automatically by using the software.The results show that the software system can satisfy the requirement of flaw detecting performance index,and has the engineering guidance significance for study of thick wall pipe flaw detecting.