Wavelet decomposition method was used to decompose the welding current of VPPA,high frequency pulse VPPA and highlow-frequency pulse VPPA into 6 different bands. The average energy of each frequency bands in the different welding methods was calculated and compared,the average energy of same frequency bands for different welding methods was contrasted simultaneously. It is found that the addition of high and low frequency pulses will affect the distribution of frequency band energy,but the whole frequency distribution is well-distributed. It is more remarkable for high frequency the influence of low frequency pulses on the average frequency band energy than high frequency pulses.