Abstract: The common negative pressure wave based pipeline leakage detection technology is to locate the leakage based on the time difference of the negative pressure wave reaching the upstream and downstream obtained by calculating the pressure drop point. However, the locating accuracy of leakage is reduced for the pressure drop point is not obvious due to the influence of propagation attenuation of pressure wave, little pressure variation in slow leakage and interference of noises. In order to reduce the locating error of the negative pressure wave based leakage monitoring technology, the propagation time difference of the negative pressure wave transmitting to the upstream and downstream can be obtained by calculating its similarity with Euclidean distance based on its homologous characteristics, which can be further converted into the location of leakage. By field test, the results indicate that: In this way, the abrupt and slow leakage of pipeline can be located accurately, the deficiency of the original negative pressure wave based pipeline leakage monitoring technology for inaccurate locating of slow leakage can be compensated, and the performance can be realized by simply upgrading the original system.