Using polyethylene glycol diacrylate as carrier materials, respectively with N, N, N, ‘N’-tetramethylethylenediamine (TEMED) as promoter and potassium persulfate (KPS) as initiator to immobilize anaerobic ammonium oxidizing bacteria. Orthogonal experiments were used to optimize immobilization conditions of anaerobic ammonium oxidation bacteria:10% PEGDA monomer, 0.25% KPS, 0.5% TEMED, the optimum operation condition was to control the polymerization temperature at 20℃, polymerization time was about 5min, The ratio of bacteria to gum was 1:1. The continuous flow experiment of immobilized pellets showed that after a short period of activity recovery, the nitrogen removal effect was continuously improved,and it had a certain impact resistance to the increase of hydraulic load. The scanning electron microscopy (SEM) showed that the immobilization materials have good biocompatibility and good mass transfer performance. High-throughput sequencing showed that after a period of time of stable operation, the microbial diversity in the pellets decreased slightly. And the Candidatus Kuenenia that belongs to anaerobic ammonium oxidizing bacteria which accounted for 6.58% of the total microbial system was up to 9.8%, the changes in microbial population showed that the performance of anaerobic ammonium oxidation could be improved greatly after immobilization.