Abstract: Calibrating the emission parameters of ultrasonic flaw detectors is a key aspect in ensuring the accuracy of inspection results. Nevertheless, the calibration results are subject to various influencing factors. This paper analyzed the main error sources during the calibration of emission parameters, relying on international standards (such as ISO 22232-1:2020 and EN 12668-1:2010) and domestic standards (such as GB/T 27664.1—2011 and JJG 746—2024).It was found that oscilloscope settings (e.g., the measurement position of pulse width), load characteristics (e.g., impedance stability), and standard discrepancies significantly affected the calibration results. Through comparing the impedance characteristics of different loads at high frequencies with actual test data, the inapplicability of loads like wire-wound resistors in high-frequency scenarios was validated. Additionally, operational specifications (e.g., calibration of oscilloscope probes) and cable selection were also vital for measurement accuracy.The research results provided optimization suggestions for the calibration of ultrasonic flaw detector emission parameters, emphasizing the importance of strictly following standards and choosing suitable equipment.