Abstract: Through the experimental study of the efficient nitrogen and phosphorus removal technology by magnetic microfiltration membrane method, the effect of process one "micro-magnetic flocculation reaction system-magnetic microfiltration separation system-Bio-O aerobic tank" and process two "Bio-O aerobic tank-micro magnetic microfiltration separation system" was compared and studied. The phosphorus removal capacity of biochemical process(Bio-O aerobic tank) and the influence on the dosage of chemical process(magnetic microfiltration) were investigated.The results showed that the magnetic microfiltration averaged 94% of total phosphorus removal, the Bio-O aerobic tank removed more than 90% of ammonia nitrogen, and the nitrification load was up to 0.33kgNH₃-N/m³/d. In process two,the biochemical process is set before, the biological phosphorus removal of Bio-O not only reduced the dosage of the posterior magnetic microfiltration process, saved 40% in the dosage of the agent, but also helped to improve the stability of the overall process of the magnetic microfiltration membrane method, and the system impact resistance was higher load. In comprehensive consideration, the process flow two was more suitable for sewage nitrogen and phosphorus removal. While reducing the amount of physical and chemical dosage, the total effluent phosphorus and suspended solids could ensure the standard stably.