Abstract: The national standard of NB/T 47013.3-2023 (hereinafter referred to as the 2023 edition) has been released, and the performance requirements for A-scan pulse-echo ultrasonic flaw detectors are mainly concentrated in Appendix A. In the actual application process, Appendix A only clearly defines the limit values of various performance indicators. The regulations regarding technical details such as specific test conditions, operation steps and other technical details are more concise compared to other calibration standards for ultrasonic equipment, making it difficult for third-party testing institutions to establish a complete testing capabilities for ultrasonic flaw detectors based on this appendix. On the other hand, there is a widespread demand among enterprises engaged in the special inspection of pressure equipment for ultrasonic flaw detector testing reports based on Appendix A of 2023 edition standard. Therefore, the research on practical testing methods for the parameters listed in Appendix A holds significant value for engineering applications. This paper conducts a comparative analysis with the internationally universal ultrasonic flaw detector testing standard of ISO 22232-1:2020, and investigates the testing implementation methods for each parameter. The results show that the test methods specified in standard of ISO 22232-1:2020 are more systematic and detailed. Through experimental verification of selected parameters such as transmitter pulse voltage, dead time after transmit pulse, dynamic range and the assessment of measurement uncertainty, the feasibility and validity of adopting the test method specified in standard of ISO 22232-1:2020 to replace Appendix A of 2023 edition standard for testing verification are validated.