The current biological process for coking wastewater treatment requires the combination of several units with different methods. In addition, the mechanism of how the pollutants would be degraded along the whole plant is still not yet defined. All these consequently prevent targeted optimization to be conducted. To tackle these problems, a membrane-less air-cathode microbial fuel cell was constructed in this paper. Cyclic voltammetry and polarization were carried out to characterize the electrochemical performance of MFCs, while infrared spectroscopy, colorimetric methods and pyrosequencing were applied to trace the changes of chemicals and microbial communities in the reactor during the batch. The results revealed that sulfur-containing inorganic compounds in coking wastewater were degraded at the first, followed by the degradation of phenols. After that, nitrogen-containing pollutants were then removed through a combined pathway of aerobic nitrification and anaerobic denitrification. The degradation of long chain alkanes happened at the later phase of the batch. In addition, it was found that the microbial community structure was highly dependent on the available nutrients presented in the liquid phase. Desulfurella and Flavobacterium were dominant in the community in the early stage to perform aerobic decomposition of sulfurous and phenol pollutants, which would be latterly taken over by Nitrospitrae, Alcaligenes and Thiobacillus for nitrification and denitrification. The maximum power density of the MFC achieved was 12.5mW/cm², of which the cell voltage was 470.9mV. The total removal efficiencies of COD, T_Phenols, T_sulfur, TN and NH₄⁺-N were 85.8%, 83.3%, 87.5%, 43.8% and 89.9%, respectively. All these data demonstrated the feasibility of a one-step process for coking wastewater treatment using microbial fuel cell.