Abstract: In order to analyze the characteristics of electrical signals in VPPA-MIG hybrid welding of Aluminum alloy. The VPPA arc electric signals and the MIG arc electric signals were acquired by the VPPA-MIG hybrid welding signal Acquisition system,and the power spectrum of the acquisited electrical signals was analyzed after the wavelet de-noising. The DC component is found in the MIG arc electric signals by the power spectrum analysis of the 15 groups of experiment,and its’ power accounts for a large proportion of the power of all frequency components. When the varying frequency of positive and negative polarity of VPPA arc is constant at 100 Hz,main high frequency components of MIG arc electric signals and their harmonic components get greater with the increment of the current of MIG arc. The change of welding speed can affect the power ratio of main high frequency components in MIG arc electric signals and their harmonic components,while the change of the current of VPPA arc cannot affect the main high frequency components of MIG arc. Main frequency components of VPPA arc signals contain DC component,100 Hz and its sub harmonic components,which are not affected by VPPA arc current,MIG arc current and welding speed.