Abstract: Measurement error of flowrate affecting on accuracy of locating system of pipeline leakage is studied, for example of rotary flowmeter the cause of error resulting in dynamic metering is discussed, and first time to present a regression metering error curve by interpolation of third power of sample stripe, correcting dynamicly metering error causedby slide flow of rotary flowmeter, which can obviously promote the sensitivity of pipeline leakage detection and the locating accuracy.