The wastewater originated from the production of acrylonitrile-butadiene-Styrene (ABS) resin was treated by biological activated carbon (BAC) to investigate the characteristics of adsorption and biodegradation of BAC for ABS resin wastewater and the removal mechanism of the organic pollutants. The results suggested that bioregeneration was the key to BAC, and it could make BAC reach more than 80% of COD, TOC and total kjeldahl nitrogen (TKN) removal efficiency after the 100th run. Abundant microorganisms were observed on the surface of BAC including long-stem bacteria, vorticella and coccise, which indicated that BAC could protect the microorganisms from the shock loadings of toxic, refractory and complicated ABS resin wastewater.