Abstract: In order to meet the requirements of nuclear fusion experiments, the converter is required in the design of the next generation tokamak to output instantaneous high-intensity pulsed current for providing type test dynamic and thermal stability in large electrical equipment. In this paper, a method of equating the impedance of the power supply system to the secondary side of the transformer and combining the voltage change relationship at both ends of the converter is presented. The total output current of several converters is obtained by calculation in different electrical parameters. The calculating process and results of electrical parameters meeting the requirements are given when the output current is 1 MA. The results are the limit condition under the given parameter, which makes the minimum design threshold in the high-power converter impulse current design, and lays the foundation for the following converter device selection and structure design.