In this study，o-CP，m-CP and p-CP were selected as the target pollutants, and then the performance and mechanism of electroreductive dechlorination of mono-chlorophenols on inert（GC） and catalytic（Ag and Pd） electrodes were studied by cyclic voltammetry（CV）. In addition, this study also explored the impact of molecular structure on the process of electrochemical reduction of mono-chlorophenols. The results showed that all the obtained values of k of these three types of mono-chlorophenols from GC electrode were all greater than 0.5, indicating that reductive cleavage of C-Cl bond on GC electrode followed a stepwise mechanism. Nevertheless, a noticeable positive shift of the reduction peak potential of mono-chlorophenols on Ag and Pd electrodes was observed. Pd exhibited excellent electrocatalytic properties towards dechlorination of mono-chlorophenols. Moreover, the involved values of k on catalytic electrodes（Ag and Pd） were far less than 0.5，which indicated that reductive cleavage of C-Cl bond followed a concerted mechanism. This research further showed that the electrocatalytic dechlorination reactivity of these three types of mono-chlorophenols followed a descending trend as p-CP>m-CP>o-CP. This phenomenon was mainly due to the existence of steric hindrance, which made it the most difficult for chlorine atom at ortho-position to combine with the electrode surface. In addition, the values of the lowest unoccupied molecule orbital energy（ELUMO） of these three types of mono-chlorophenols followed a descending order as: o-CP>m-CP>p-CP, indicating that the reductive dechlorination of mono-chlorophenols followed the opposite order. Finally, based on the molecular structure characteristics of mono-chlorophenols, the parameter ELUMO was selected and successfully developed a good linear free energy relationships（LFERs） with the electroreductive dechlorination reactivity in this research.