Aiming at problem that the seepage of rock and soil is difficult to be monitored in situ,a tracing method of electrolyte pulse generated by electrolytic polarization is proposed. The measuring principle,structure and measurement and control circuit of sensor are introduced. The sensor is made by using copper clad laminate with the size of 20 mm × 5 mm,and flow velocity measurment experiments is conducted in 6 mm diameter of organic glass tube to simulate a single crack. The results show that the structure o...