The design treatment scale of phase I project of a WWTP in Huizhou City is 1.0×10⁴ m³/d, the "A/A/O oxidation ditch +high efficiency sedimentation tank + rotary fibre-plate filter" treatment process was adopted. Due to increased discharge of domestic sewage, the treatment capacity of the phase II expansion project was 2.0×10⁴ m³/d and the phase I project was reconstructed in 2020, the main treatment process was UCT+high efficiency sedimentation tank + Rotary microfilter. The operation results showed that the eflluent quality stably met the stricter values of discharge standard of water pollutants in watershed of DanShui River and ShiMa River (DB 44/2050－2017) and of first level A criteria in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918－2002) in 2023, the average annual removal rate of COD_cr, BOD₅, SS, NH₃-N, TN and TP increased by 4.87%, 5.93%, 1.87%, 0.67%, 7.97% and 2.27% compared with 2019, respectively.