A negative voltage generating circuit having an automatic voltage adjustment function, comprising a negative voltage generating circuit and a feedback control module. The negative voltage generated by the negative voltage generating circuit is adjusted by means of the feedback control module. The negative voltage generating circuit having an automatic voltage adjustment function can automatically adjust the charge current of a charge pump according to a load current, thereby achieving a stable output voltage, such that a traditional analog circuit structure can operate normally even at a very low power supply voltage, and the circuit is especially applicable to deep submicron processes. Moreover, said circuit can also achieve a digitally adjustable output voltage, i.e. it no longer only outputs a negative voltage, and can adjust, according to actual needs, the negative voltage value that needs to be outputted.