Compared GJB151B RE102 test method lower than 30 MHz frequency band with that of GJB151A, the rod antenna grounding network and the height are changed greatly, which directly influences the accuracy of measurement results. To research the influence of the changed test method on measurement results, simulation and experimental methods are utilized, the different measurement results caused by different grounding network and the height of rod antenna are analyzed based on the circuit theory and electromagnetic theory. Finally, the paper concluded that the radiated emission results by GJB151A standard are 5~10 dB higher than that of GJB151B in 2~30 MHz frequency band. These measurement results also show that the GJB151A test setup will lead to resonance phenomenon. Furthermore, the power cord is the main reason that RE102 measurement results exceed the limit line at low frequency. The research will promote the implementation of GJB151B, help EMC engineers to understand the impact of grounding for EMI test and analyze RE102 measurement results of electronic equipment. It also helps them to handle results exceeded limit line and abnormal results, and to avoid giving misjudgment about radiated emission of electronic equipment.