To improve the pollutant removal efficiency of anaerobic baffled reactor(ABR),the influence of or-ganic loading rate(OLR)on the treatment system was investigated based on adjustment of influent COD con-centration and hydraulic retention time(HRT).The available volume of the ABR was 28.75 L.The results indicated that the adjustment of influent COD and HRT with the OLR ranged from 4 to 5.4 kg·m-3 ·d-1 could make all kinds of function flora that participated the anaerobic digestion process distribute more orderly in the ABR system,and the pollutant removal efficiency and the stability of the reactor were improved effec-tively.A COD removal rate above 90%can be achieved in the ABR when OLR is 4 kg·m-3 ·d-1,the in-fluent COD is 8 000 mg·L-1 and HRT is 48 h.