A novel electrochemical method was proposed to estimate the effective electroactive area, active volume and surface coverage of the porous three-dimensional film electrode. Nickel hexacyanoferrate (NiHCF) thin films were synthesized on the porous three-dimensional foam nickel substrate by cathodical deposition. Cyclic voltammograms of the foam nickel electrode and the NiHCF film electrode at various potential scan rates were obtained in alkali metal solution with and without K3Fe(CN)6, respectively. The effective electroactive area and the coverage of the porous three-dimensional film electrode were characterized by the reversible property of redox reaction of porous electrode in different solution systems. Combining with chronocoulometry, the active volume of the internal NiHCF film was obtained, and then the average thickness of the film was also calculated. The proposed method shows the characteristics of fast response, high sensitivity and excellent accuracy with easy operation and good reliability.