An adjusting device of an output voltage of a switch power supply and an adjusting method are provided. The adjusting device includes a potential setting module generating a high level signal and an adjustor being connected to the potential setting module to receive the high level signal. The adjustor includes a signal emitting module and a comparison module. The signal emitting module emits a pulse drive signal to the switch power supply when receiving the high level signal. The switch power supply automatically adjusts the output voltage when receiving the pulse drive signal. The comparison module reads the output voltage, compares with a preset voltage, and adjusts the output voltage according to a comparison result. The switch power supply can stop the automatic adjustment when an output level of a switch port of the switch power supply is inverted. An integrated chip is also provided.