Abstract: Large-depth induced polarization sounding requires power supply with long wires and high current. This results in the oscillation of the turn-off waveforms, which greatly affect the accuracy of induced polarization (IP) measurement. To address this issue, this study first constructed a simulation model for electromagnetic induction caused by the long wires for high-power IP transmitters and proposed a method to eliminate IP electromagnetic coupling using an RCD absorption circuit. Then, using the optimal absorption circuit algorithm, the parameters of the optimal absorption circuit were calculated. Afterward, the optimal absorption circuit of the high-power 30 kW IP transmitter was designed, and the simulation results indicate that the optimal absorption circuit effectively mitigated the oscillation of turn-off waveforms. Finally, based on the optimal absorption circuit, a high-power IP transmitter prototype was developed. An AB/2 configuration with a large electrode spacing of 1 500 m was deployed in an area of Shanxi Province. The full turn-off waveforms at four measurement points were repeatedly observed under an emission current of 10 A. With a maximum standard deviation of polarizability estimated at 0.02, the accuracy of the transmitter met the requirements of relevant specifications.