Under laboratory conditions, it is challenging to perform the high-field-intensity radiation sensitivity measurement on the two-wire coupled channel of the equipment under test (EUT), and the current equivalent measurement method is useless for nonlinear systems. The calculation is performed by building the response calculation model of the EUT under radiation and injection circumstances. The linear correspondence between the injection source and the radiation field is determined on the basis of utilizing a high-linearity current probe with a primary turn larger than 1. The equivalent measurement method for high-field-intensity radiation sensitivity of the two-wire interconnection system is optimized, and the nonlinear EUT can also be applied, which is closer to the actual situation under the radiation conditions and simplifies the operation steps. The CST software and the laser distance measurement sensor test are verified, and the test errors are less than 3 dB, which complies with the engineering requirements.