This paper describes an improved one-step voltage pulse detachment method by using perchloric acid and ethanol mixture as detaching solution for the preparation of through-hole porous anodic alumina (PAA) membranes. The detachment of PAA from aluminum substrate and the dissolution of the barrier layer can be completed simultaneously in the detachment solution by applying a pulse voltage in situ after the anodization process. The influence of voltage pulse height and nature of the detachment solution on the efficiency of detachment have been systematically investigated. The present procedure is more environmental friendly and efficient as compared to the conventional electrochemical detachment methods and is promising for the preparation of freestanding PAA films with through-hole morphology which are important for nanomaterials synthesis and nanoscale separation.