A composite electrode was prepared by electrodepositing palladium nanoparticles on an interlayer film composed of polyaniline-nickel hexacyanoferrate-carbon nanotubes. Scanning electron microscopy and cyclic voltammetry were employed to systematically characterize and analyze the electrodes. The dechlorination properties were investigated using 4-chlorophenol as a model pollutant and the operating conditions were optimized. The results indicated that the palladium particles presented as spike-like clusters. As compared with the electrode without the interlayer, the composite electrode exhibited a better electrocatalytic activity and stability towards dechlorination because of its higher hydrogen adsorption/desorption charge. The dechlorination efficiency for 4-chlorophenol (100 mg/L) reached to 98.59% in 120 min under the optimum conditions. The corresponding current efficiency was 12.85%, and the predominant product of dechlorination was phenol. The interlayer significantly improved the stability and the performance of the composite electrode although the palladium loading was very low (0.53 mg/cm())(-2).