Abstract: By analyzing the waveform recorded by the same seismological observatory equipment based on different power supply systems,we calculate the self-noise power spectrum density of the signal outputted by the power supply systems and analyze the interdependency between the waveform recorded by the same seismological observatory equipment and the signal outputted by the power supply systems.We get the character of the signal outputted by different power supply systems and quantify the relationship between the waveform recorded by the same seismological observatory equipment and the signal outputted by the power supply systems.The result of the experiment shows that the change of power supply system can improve the quality of waveform record.