In order to solve the problems of the original test method in the acceptance test of an electronic countermeasure system, such as high requirements for test equipment and long test time, an improved method is proposed. A common oscilloscope is used to replace a high-speed oscilloscope, a detector is added at the front end of the radio frequency to detect the radio frequency signal, and the interference reaction time is the time difference value of the change of the detection signal of the radio frequency signal output by the signal source and the interference signal output by the jammer from low to high, so that the requirements on the test equipment are reduced, and the test time is shortened. The analysis and experimental results show that the improved method is effective and feasible without affecting the accuracy of the test.