In order to enhance the sludge organics degradation rate in sludge wetland treatment system, this paper for the first time combining the bioelectrohenesis with STW system to improve the performance of STW and recovery biomass energy simultaneously. The degradation rate of sludge and power output under different organic loading of the MFC-STW system, using Canna as wetland plants, were investigated. Experimental results showed that both of the output voltage and power density of MFC-STW system increased significantly with the increasing of sludge loads. The maximum output voltage and power density of the MFC-STW system under steady-state operation were 0.794 V and 0.268 W/m³, respectively. During the charged circulation period, moisture content of the bottom layer sludge in MFC-STW system reached 84%, which was 7% lower than that in the with a STW system with no electricity production. Moreover, the average TCOD degradation rate of MFC-STW system was 74%, was 11% higher than the blank test. Bioelectrogenesis could improve the performance of sludge dehydration and degradation during sludge wetland treatment.