The pollutant removal efficiencies of the bacterial-algae symbiotic system supported by head aeration and membrane aeration under different operating conditions were compared to explore the removal mechanism. Results showed that, in the MABAR (based on membrane aeration), the removal rate of NH₄⁺-N, total nitrogen (TN), PO₄sup>3--P, and COD were soared by 1.44,21.22,3.08,52.09 kg/m²/m³, respectively, compared to HABAR (based on aeration head aeration).In terms of algae accumulation, the algae accumulation concentration of MABAR in 5 stages are higher than that of HABAR, with a highest increased concentration by 15.17 mg/cm². These phenomena not only due to no-stripping and high carbonization ability of membrane aeration to provide sufficient inorganic carbon for autotrophic algae, but membrane aeration also provides a good living environment for the bacteria which has the function to stimulate algae growth, such as Acidovorax, Rhodobacter and Acinetobacter. In summary, MABAR can not only promote the removal efficiency, but also help the photobioreactor to resist shock and maintain stability. This new reactor provides a new operating mode for the practical application of the photobioreactor in the future.