Abstract: Nodes of the offshore platform structure pipe are mainly in the form of T, K and Y types, and it is difficult to detect flaws in tube node weld by ultrasonic testing. This article was to describe the test preparation, implementation，positioning of the defects and defect judgment in detail, and what is more, full instructions for the testing techniques and attentions were given for effectively solving the problem of site working, which provided a good reference for ultrasonic inspection of tubular joint weld.