Abstract: According to the demand for detection of the transverse defect of the iron-nickel-based alloy seamless pipe,the suitability and the optimization direction of the radiographic testing (RT)technique are systematically evaluated.The detection abilities of the two detection methods,i.e.,the radiographic film imaging process and the digital imaging process are comparatively analyzed,and then verified with the detection results from conventional testing methods such as UT,ET and PT,etc. It is concluded that RT method is suitable for detecting seamless steel pipes with OD over 114 mm and WT. ranging from 1 mm to 40 mm,being capable of finding out the pitting defects with diameter ≥0.2 mm as well as the linear defects with length ≥2 mm. And the method can also be used to obtain the detection rate of 100% of the axial and transversal(circumferential)linear defects,and the overall false alarm rate 5%. The research achievement provides a reliable solution for high-precision NDT of the iron-nickel-based alloy materials,and the method has been applied to quality control of actual production lines.