The electrical control system of music fountain based on PLC and frequency converter can realize two functions: first, the fountain water column changes according to the strength of the music rhythm. The specific implementation is that the PLC analog module will detect the audio signal transmitted to the PLC host for processing, after amplification, in the conversion of analog to control the inverter, through the setting of the inverter parameters, the output frequency of the inverter with the audio signal strength to change. Thus, the speed of the water pump is controlled and the height of the fountain water column is changed.