It was tested that the excess sludge reduction rate could be 23 wt% in aerobic reactor that is inoculated with aquatic worms,called worm reactor, connected to sequencing batch reactor (SBR)based on effluent discharge standard requirments.The distribution of velocity field, volume fraction of air and turbulent intensity in worm reactor were numerically simulated by computational fluid dynamics (CFD) with the models of Eulerian two-phase flow and Standard k-ε turbulence provided by ANSYS FLUENT 16.0 software. The results showed that the internal flow field of worm reactor was suitable for worm SingestionSof sludge when the aeration was about 0.2m3/h and worms were placed in position P2 where worm density was 1.63g/dm3. Subsequently, the sludge reduction rate achieved by the maximum of 23 wt%. This reduction rate was basically consistent with the predicted value of Box-Behnken Design (BBD), which further proved the reliability of the numerical simulation. Therefore, CFD simulation may guide worm-reactor performance_Sefficiently, andSas well as SlayStheSfoundationSforStheSfutureSSstudySof scale-up andSSengineeringS application of sludge reduction with worm-feeding.