Cake fouling mechanism was studied for membrane bioreactor (MBR) treatment of synthetic coke wastewater. Cake fouling characteristics of the aerobic activated sludge from MBR was investigated. The experimental results demonstrated that the cake governing equation fit the entire cake microfiltration (MF) process while cake fouling model was applicable to simulate the decrease in permeability and was used to predict the cake fouling development for both PVDF and PP MF membranes. Based on four-step development progresses, cake formation mechanism had been depicted with the increasing of TMP and the reduction of the cake porosity ratio. In addition, the comparison experiments under different operation modes were performed to further analyze the cake governing mechanism for MBR filtration.