Abstract: This paper proposed a quantitative evaluation method based on autocorrelation analysis,to extract the coefficient of variation of intervals between autocorrelation function peaks from arc welding voltage and current signals,which were then used as the quantitative values to evaluate the metal transfer process stability in arc welding.Experiments showed that results obtained through this method were consistent with those from manual analysis.Besides,the combination of the quantitative values obtained through this method and other quantitative values has preferably realized the automatic evaluation evaluation of dynamic characteristics of power supply for CO₂ arc welding.The recognition accuracy reached 97.4359%,which was quite close to the standard of practical use.