Abstruct:In view of the nonlinear characteristics of MAG arc welding signal which is time-varying very quickly,and there are various interference in the process of signal acquisition,this paper adopts wavelet analysis to remove noise inter-ference.By analyzing the filtered voltage and current contrast curve,the typical voltage and current history principle of MAG welding in short circuit mode is summarized,and the real-time resistance variation trend in welding process is ana-lyzed.This paper analyzed the maximum probability density value of voltage and current under the condition of arc welding by drawing the probability density diagram of arc welding electrical signal and the volt-current curve,as well as the droplet transfer cycle in arc welding process and the short circuit duration in each cycle,and found that the short circuit duration and the droplet transfer period showed a certain correlation.