Abstract: The X-ray Digital Technology was developed, aiming to overcome the shortcoming of low efficiency, high cost and environmental pollution for film detection method, and poor sensitivity for image intensifier real time imaging method existing in the present X-ray inspection for the weld seam of Submerged Arc Welded Pipes. The technology used a linear CCD, and realized the X-ray reception and image inversion, and through the following up treatment, the detection sensitivity reached or exceeded the level of film detection method, and fully better than the level of image intensifier real time imaging method. After using in the production, it made a good performance, and the static sensitivity reached 1.3%. The technology can be adopted as RT method in the API 5L and ISO 3183 line pipe specification, so it is worth popularizing and applying.