Abstract: Design of the existing weld pipe X-ray detecting system of a certain domestic company is conducted，involving such details as changing the image receiver structure from the hanging type into a standing type，and changing the detecting arm lifting device from the weight type manually-operated screw into a dual-spiral lifter.Thanks to the design modification，the detecting system is now capable of automatic quick adjustment as per size change of pipes so as to cut down the auxiliary time，and thus enhance the productivity，having been satisfactory to the requirements for the detection operation.