According to the characteristics of the ATT7022E metering chip, this paper analyzes the harmonic analysis method based on ATT7022E power quality monitoring. FFT is mainly studied as harmonic analysis algorithm in ATT7022E practical application,this researchconducts the experiment for synchronous sampling and ADC sampling these two methods of harmonic analysis. Experiments show that under the condition of the random variation signal, this method of harmonic analysis has certain reference value in engineering application.