通过对“十五”台站水位数据干扰原因进行调查分析，得到一类受电信号变换干扰影响明显的台站。通过对该类台站的水位数据进行小波分解，利用小波模极大值原理，得到水位受明显干扰的时刻。通过对多个台站不同时段内电信号变换影响的水位数据分析，得到该类干扰的典型动态，以及识别方法。

A dynamic condition of water level that was interfered by the changing of electric voltage has been found through the investigation and research to the “the tenthfive year plan” digital water level data. Using the wavelet decomposition and the Wavelet transform modulus maxima method to the data of water level, we can fix the moment of the interference. After that, we carried the comparative analysis of the water level data from different stations and then we got the typical dynamic characteristics of the interference and the way to identify it.