Wastewater in bicycle factory has the characteristics of low pH, high quantity,high organic content, BOD5/CODcr<0.5, poor biodegradability and high TP and SS，so firstly,wastewater must be pretreated by  physical and chemical treatment，secondly combine with A/O process to remove  the organic matter  and TP,finally, wastewater is treated by activated carbon adsorption process. Through above treatment process, the effluent of wastewater can achieve the level of the national discharging standard.