Abstract: In order to realize a study on the focusing double frequency induced polarization method,an excitation signal transmission system of the advanced water de tection was designed for the focusing double frequency induced polarization method.The paper provided the detail design process of the key circuits.A prototype was manu factured and was applied to the study on the mine roadway simulation experiment in the lab.The system could send five circuit same frequency and same phase modulated excitation square wave current signals and the five channel signal amplitude was a single channel adjustable in order to establish a controllable focusing detection current f ield. In addition,based on an isolation constant current power designed according to the switch power principle,a secondary constant current circuit was added to the syste m and the wave form of the output excitation signal was improved.Meanwhile an isolation treatment was conducted on all control signals and sampling signals related to th e main control system with the linear isolation circuits and isolation was conducted on all driving signals in the inverse circuit in order to ensure the five channel excitation signals outputted could keep single circuit,continuous ,stable and adjustable.