Abstract: Natural gas is one of the main clean energy sources, so the measurement of natural gas becomes more and more important. With the technological development, ultrasonic flowmeter has become the major instrument in high flowrate, high pressure, large diameter gas measurement. However, the flowmeter of gas metering system cannot be calibrated on site, which raises the cost and decreases the usability. According to the related standards, acoustic velocity verification can extend the calibration period of ultrasonic flowmeter. We introduce the principle and method of acoustic velocity verification and describe the typical application of this technology on offshore gas platform. It is shown that acoustic velocity verification can improve the usability of the gas metering system, and thus reduce the production cost and increase the production efficiency.