Abstract: In the crude oil transportation system in Linyi Pump Station (built in 2008), UFM3030 ultrasonic flowmeter is used. Its high-precision measurement contributes greatly to the transportation in the pump station. However, the flowmeter shows low precision when measuring Shengli Crude which is transported via large-diameter high-throughput pipeline. According to the system process, the composition and principle of the ultrasonic flowmeter are introduced, and the errors occurred when UFM3030 is used in the system are analyzed. Results show that the accuracy of UFM3030 is related to the Reynolds number of crude oil. In other words, the errors of the flowmeter are primarily caused by oil, temperature and throughput (or diameter). Accordingly, it is suggested that, at the outlet manifold of oil-feed pump of Shengli Crude and the offtake line of Lu-Ning Oil Pipeline, the five-channel ultrasonic flowmeter is used, which is not affected by Reynolds number. In this way, the measurement errors may be minimized.