Potassium sorbate wastewater contains highly concentrated organic substances and high salinity, which can be biodegraded easily. T he inlet COD_Cr concentration of the wastewater is 8 000~ 16 500 mg/ L, B/ C value is more than 0. 5, salt concentration is more than 15 g/ L. Submerged anaerobic filtration and activated sludge process with membrane are used in this method. The removal efficiency of COD_Cr is 93% ~ 99%, and the COD_Cr concentration of outlet water is less than 300 mg/ L. It has completely reached the Second Grade Dis- charge Standard GB8978 ? 1996, and has been checked and accepted by the local environmental protection orga- nization.