Pd/Fe bimetallic particles were synthesized by chemical deposition and used to dechlorinate 2,2′,4,5,5′-pentachlorobiphenyl in soil. Batch experiments demonstrated that the Pd/Fe bimetallic particles could effectively dechlorinate 2,2′,4,5,5′-pentachlorobiphenyl. Dechlorination was affected by several factors such as reaction time, Pd loading, the amount of Pd/Fe used, initial soil pH, and 2,2′,4,5,5′-pentachlorobiphenyl concentration. The results showed that higher Pd loading, higher dosage of Pd/Fe, lower initial concentration of 2,2′,4,5,5′-pentachlorobiphenyl and slightly acid condition were beneficial to the catalytic dechlorination of 2,2′,4,5,5′-pentachlorobiphenyl. The degradation of 2,2′,4,5,5′-pentachlorobiphenyl, catalyzed by Pd/Fe followed pseudo-first-order kinetics.