The problem of electromagnetic compatibility caused by supraharmonics in the frequency range of 2kHz ~ 150kHz in the power grid is becoming increasingly prominent. but the relevant IEC standards have not yet given the standard measurement method, which directly affects the technical supervision and management of related electromagnetic compatibility. By comparing and studying the differences and shortcomings of the standards IEC 61000-4-7 and IEC 61000-4-30 on the measurement methods of supraharmonics, this paper puts forward the appropriate improvement measures. Then we use the improved measurement method to simulate and analyze the typical signals, and study the influence of the difference between different measurement methods from the perspectives of spectrum leakage, aggregate bandwidth, and amplitude modulation detection. Finally, the effect of each measurement method is comprehensively evaluated by the measured data, and the application suggestions are given, which can provide a reference for the unified measurement of supraharmonics in the range of 2kHz ~ 150kHz.