Abstract: Aiming at the problems of complicated, energy-intensive and costly fracturing backflow fluid treatment technology,electrodialysis tests were conducted to verify the feasibility of electrodialysis as the pre-treatment of MBR biochemical treatment system,which was based on the analysis results of fracturing backflow fluid quality. The tests showed that the total suspended solid(TDS) of fracturing backflow fluid was negatively correlated with the COD removal rate of wastewater. At the same time, the optimal design conditions of wastewater biochemical reaction were verified by controlled experiments. A two-step core treatment method coupling electrodialysis and biofilm treatment was established to significantly improve the COD removal rate, which made the backflow fluid water clear and transparent after treatment. Therefore, it was possible to replace the advanced oxidation process with a biochemical system in lower operating costs, and it would also provide a theoretical and practical basis for large-scale industrial application.