Abstract: The understanding and application of GB/T37910.1-2019 Nondestructive testing of welds. radiographic acceptance level. part 1: steel, nickel, titanium and their alloys standard is introduced mainly from the scope of application, acceptance level, defect type, evaluation area division, defect assessment, etc. The standard is suitable for the evaluation of the defect of technical images of the film method and the digital method. The traditional film method is negative image display, and most of the font technology equipment software has the function of image positive and negative image display, which can be switched according to user habits. During the evaluation, attention should be paid to the difference between the positive and negative images of the two detection technologies.