Theoretical analysis and practice experience has shown that, it is an important foundation for the judgement of the power transformer’s state to analyze the characteristics of vibration signal on power transformer surface and the characteristics of vibration signal can be used to analyze and judge the work state of the winding and iron core. Power spectrum of surface vibration signal of the running power transformer and the relationship between power spectrum and load current is analyzed. It can provide some reference for the power transformer vibration analysis.