Abstract: The probe arm lifting device of the convenient X-ray industrial TV detecting system for weld pipes stays with such disadvantages as limited adjusting range,high labor intensity and frequent jamming of the guide sleeve. To solve these problems,the design of the said device is modified,focusing on removing the weight box,and changing of the lifting type by employing a guide wheel type probe arm lifting structure. The modification has brought about a lots of advantages,namely,smooth lifting/lowering movement,easy adjustment,cut down of failure rate of the equipment,and larger adjustment range to meet the inspection requirements for different steel tube sizes.