Abstract: High intensity radiated field (HIRF) cannot be simulated under the condition of laboratory presently, so it is hard to carry out electromagnetic radiated susceptibility and safety margin test for system with single radiation method In order to solve the problems, the testing technology of using injection as a substitute for electromagnetic radiation is explored The equal response voltage on the equipment cable port is regarded as equivalent principle The equivalent correspondent relation between injection voltage and radiated field is put forward theoreticallyThe conditions used to extrapolate injection voltage in HIRF are determinedThe equivalent injection new method based on coupling module is proposedOn the basis of theoretical analysis, the typical nonlinear interconnected system is selected as equipment under test, and the single frequency continuous wave radiation and injection effect experiments are carried out separatelyThe test results indicate that the relation between radiated field and injection voltage is linear, and the equivalent injection voltage used to substitute HIRF test can be obtained by linearly extrapolating the correspondent relation in lower radiated field Furthermore, the test results also verify the validity of the test method proposed in this paper.