Palladium-polypyrrole-foam nickel composite electrode (Pd/PPY(PTS)/Ni) was prepared through electrodeposited of palladium nanoparticles onto preformed electrodes (surface of electrodes was coated with potentiostatic electropolymerized polypyrrole). The stability of the fresh and used composite electrode was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). It was found that the surface state, morphology, and crystalline structure of the composite electrode were stable after 5 recycle uses. Electrocatalytic activity of the composite electrode was evaluated for the hydrodechlorination (ECH) of six kinds of dichlorophenols (DCPs). Results indicated that 2,4-DCP showed higher hydrodechlorination rate. Further, the pathway of electrochemical hydrodechlorination of six kinds of dichlorophenol isomers was investigated.