This study aims to investigate the effect of a magnetic field on nitrous oxide (N2O) emission from a sequencing batch reactor treating low-strength domestic wastewater at low temperature (10℃C).After running for 124 days in parallel,results indicated that the conversion rate of N2O for a magnetic field-sequencing batch reactor (MF-SBR) decreased by 34.3％ compared to that of a conventional SBR (C-SBR).Meanwhile,the removal efficiencies for total nitrogen (TN) and ammonia nitrogen (NH4-N) of the MF-SBR were 22.4％ and 39.5％ higher than those of the C-SBR.High-throughput sequencing revealed that the abundances ofAOB (Nitrosomonas),NOB (Nitrospira) and denitrifiers (Zoogloea),which could reduce N2O to N2,were promoted significantly in the MF-SBR.Enzyme activities (Nir) and gene abundances (nosZ nitS and nirK) for denitrification in the MF-SBR were also notably higher compared to C-SBR.Our study shows that application of a magnetic field is a useful approach for inhibiting the generation of N2O and promoting the nitrogen removal efficiency by affecting the microbial characteristics of sludge in an SBR treating domestic wastewater at low temperature.