In the field of controlled-source electromagnetic(CSEM) exploration, high-current and high-frequency transmission is identified as crucial for the achievement of fine detection of electrical structures. However, the combined effect of inductance generated by grounded long-distance transmission lines and high-frequency currents is found to impose significant constraints on the transmitted current. Based on the calculation formula for transmission line inductance, the effects of parameters (e.g., transmission line length and cross-sectional area) on inductance were analyzed. It is clarified that the inductance of transmission lines was mainly governed by length (exhibiting a linear increase), whereas the influence of cross-sectional area is found to be weak. Combined with Kirchhoff’s laws and AC circuit theory, the formula for the effective value of the transmitted current was derived and simplified. Through error analysis, the formula was verified to meet engineering accuracy requirements. Through normalization processing, the restrictive effect of different frequency and inductance combinations on the transmitted current was quantified, and the law that the current amplitude attenuates with increases in frequency and inductance was clarified. Finally, a solution involving the introduction of auxiliary transmission wires for injecting reverse-direction currents was proposed to offset the magnetic field and reduce inductive reactance loss. The research results are shown to provide a theoretical basis for optimizing the design of transmitter parameters and enhancing the quality of deep exploration data, and are confirmed to possess important engineering application value.