The present invention provides a potentiometric titration method for measuring concentration of acid mixture of aluminum etchant, which prepares identified potassium hydroxide-ethanol solution or sodium hydroxide-ethanol solution as a titrant and uses a monohydric alcohol and a diol as an anhydrous medium for the acid mixture of aluminum etchant to carry out titration of the acid mixture of aluminum etchant so as to realize measurement of concentration of each acid contained in the acid mixture of aluminum etchant through a one-stage process of potentiometric titration thereby reducing the complication of operation of inspection and uncertainty of inspection result and achieving the purposes of carrying out inspections with high precision and high performance. The method can efficiently and accurately measure the concentrations of nitric acid, phosphoric acid, and acetic acid contained in the acid mixture of aluminum etchant.