Abstract: Taking account of the defects of routine measurements of water flow on sewage pump,the feasibility study about the method using as non-radioactive tracer was made from the theory and the practice.It was shown that the method was suitable for sewage measurement under the background of low salt density.The effects of exciting signals and temperature on results were observed.Then the revision method were proposed With the technique of data acquisition by computer,the accuracy and synchrony of this method were improved.